Cake Batter Blondies with Marshmallow Buttercream

If you’re a fan of soft, chewy blondies with the nostalgic flavor of cake batter, then you’re going to love these Cake Batter Blondies with Marshmallow Buttercream. They combine the rich vanilla taste of cake batter with the fudgy texture of blondies, all topped with a light and fluffy marshmallow buttercream frosting.

Perfect for birthdays, holidays, or any occasion where you want to indulge in something sweet, these blondies are easy to make and even easier to devour.

What Makes a Blondie Different from a Brownie?

Blondies and brownies may look similar, but they have distinct differences in flavor and texture. Unlike brownies, which rely on cocoa powder or melted chocolate for their rich, fudgy consistency, blondies have a vanilla-forward flavor with a caramel-like chewiness.

Here’s a quick comparison:

Feature	Blondie	Brownie
Main Flavor	Vanilla, Buttery	Chocolate, Cocoa
Texture	Chewy, Soft	Fudgy, Dense
Key Ingredients	Brown Sugar, Vanilla, Butter	Cocoa Powder, Chocolate
Color	Golden	Dark Brown

Cake batter blondies take this concept even further by infusing the flavor of classic cake batter, usually through a mix of vanilla extract, almond extract, and colorful sprinkles. This gives them a sweet, nostalgic taste reminiscent of birthday cake!

The Unique Flavor of Cake Batter in a Blondie

The reason cake batter blondies taste different from regular blondies is due to the combination of vanilla, butter, and almond extract, which mimics the taste of cake batter. Some recipes even use a small amount of dry cake mix in the batter to enhance the flavor and texture.

Another signature element of cake batter blondies is the addition of sprinkles, which give them a fun, festive look. Whether you’re making these for a celebration or just because you’re craving something sweet, the burst of color adds an extra layer of excitement to every bite!

Key Ingredients for Cake Batter Blondies with Marshmallow Buttercream

For the best cake batter blondie texture, using the right ingredients is crucial. You’ll need brown sugar for chewiness, butter for richness, and of course, rainbow sprinkles for that funfetti-style sweetness!

Essential Ingredients for the Blondies

Ingredient	Purpose
Unsalted Butter	Adds richness and moisture for a chewy texture. Melted butter helps bind the ingredients together.
Brown Sugar	Gives the blondies a deep caramel-like flavor and a soft, chewy consistency.
Granulated Sugar	Balances the sweetness and helps achieve the right texture.
Eggs	Acts as a binding agent and provides structure.
Vanilla Extract	Enhances the cake batter flavor.
Almond Extract (Optional)	Adds a subtle nutty sweetness, mimicking the taste of boxed cake mix.
All-Purpose Flour	Provides structure and stability.
Baking Powder	Helps the blondies rise slightly without making them cakey.
Salt	Enhances the overall flavor and balances the sweetness.
Sprinkles	A fun addition that gives the blondies their signature cake batter look!

Pro Tip: If you want an even stronger cake batter taste, you can add two tablespoons of dry cake mix to the batter. However, it’s completely optional!

The Perfect Marshmallow Buttercream Frosting

To complement the chewy, vanilla-flavored blondies, we’re making a light and fluffy marshmallow buttercream frosting. Here’s what you’ll need:

Ingredient	Purpose
Unsalted Butter	The base of the frosting, providing a creamy and rich texture.
Powdered Sugar	Sweetens the frosting while keeping it light.
Marshmallow Creme (Marshmallow Fluff)	The key ingredient that gives the frosting its fluffy texture and marshmallow flavor.
Vanilla Extract	Enhances the sweetness and balances flavors.
Heavy Cream or Milk	Helps achieve the perfect creamy consistency.
Salt	Balances the sweetness.

Why This Combination Works

The buttery, chewy texture of the blondies pairs beautifully with the light, whipped marshmallow buttercream. The sweetness from the marshmallow fluff adds a slight toasted vanilla flavor, which perfectly complements the cake batter essence of the blondies.

How to Make Cake Batter Blondies

Now that we’ve covered the key ingredients, let’s dive into the step-by-step process of making these delicious Cake Batter Blondies with Marshmallow Buttercream. Follow these instructions carefully to achieve the perfect chewy texture and rich cake batter flavor.

Preparing the Blondie Batter

Step 1: Preheat the Oven & Prepare the Pan

• Preheat your oven to 350°F (175°C).
• Line an 8×8-inch baking pan with parchment paper and lightly grease it with non-stick spray. This prevents sticking and makes it easier to lift the blondies out later.

Step 2: Melt the Butter

• In a microwave-safe bowl, melt ½ cup (1 stick) of unsalted butter in 30-second intervals until fully melted. Let it cool slightly.

Step 3: Mix the Wet Ingredients

• In a large mixing bowl, whisk together:
  • ½ cup brown sugar
  • ¼ cup granulated sugar
  • Melted butter
  • 1 large egg
  • 1½ teaspoons vanilla extract
  • ½ teaspoon almond extract (optional, for extra cake batter flavor)
• Whisk until smooth and combined.

Step 4: Add the Dry Ingredients

• Gradually fold in:
  • 1 cup all-purpose flour
  • ½ teaspoon baking powder
  • ¼ teaspoon salt
• Stir gently until just combined. Overmixing can make the blondies tough instead of chewy.

Step 5: Add Sprinkles

• Gently fold in ¼ cup of colorful sprinkles for that signature funfetti look. Avoid overmixing, as sprinkles can bleed into the batter.

Step 6: Bake the Blondies

• Pour the batter into the prepared pan, smoothing the top with a spatula.
• Bake for 20-25 minutes, or until the edges are golden brown and a toothpick inserted in the center comes out with a few moist crumbs (not wet batter).
• Let them cool completely in the pan before adding the frosting.

Making the Marshmallow Buttercream Frosting

Now that your blondies are cooling, it’s time to make the marshmallow buttercream frosting!

How to Achieve a Light and Fluffy Texture

Step 1: Beat the Butter

• In a large mixing bowl, beat ½ cup unsalted butter (softened) on high speed for 2 minutes until pale and creamy.

Step 2: Add Powdered Sugar & Marshmallow Fluff

• Slowly mix in:
  • 1½ cups powdered sugar (sifted)
  • 7 ounces marshmallow fluff (or creme)
  • 1 teaspoon vanilla extract
  • ¼ teaspoon salt
• Beat on medium speed until fully combined.

Step 3: Adjust the Consistency

• Add 1-2 tablespoons of heavy cream or milk, one at a time, and beat on high speed for 2-3 minutes until the frosting is fluffy and smooth.

Flavor Variations for a Unique Twist

Want to change up your frosting? Try these variations:

• Chocolate Marshmallow Frosting – Add ¼ cup cocoa powder for a chocolatey twist.
• Strawberry Marshmallow Frosting – Mix in 2 tablespoons strawberry jam for a fruity flavor.
• Cookies & Cream Frosting – Fold in ½ cup crushed Oreos for a cookies-and-cream version.

Decorating and Serving Your Cake Batter Blondies

Now that your Cake Batter Blondies have cooled and the Marshmallow Buttercream is ready, it’s time to put the finishing touches on this delicious dessert. Decorating your blondies not only makes them look more appealing but also enhances their texture and flavor.

Adding Sprinkles and Fun Toppings

To keep the cake batter theme, sprinkle some extra fun toppings on the buttercream before it sets. Here are some ideas:

• Rainbow Sprinkles – Keeps the funfetti look and adds a colorful touch.
• Mini Marshmallows – Adds a chewy texture to complement the frosting.
• Crushed Graham Crackers – A slight crunch for texture balance.
• Drizzle of Melted White Chocolate – Creates a glossy, bakery-style finish.

For an extra pop of color and crunch, consider mixing M&M’s into the batter or as a topping! Check out these M&M’s Brownies for more inspiration.

Topping	Purpose
Rainbow Sprinkles	Keeps the funfetti look and adds a colorful touch.
White Chocolate Chips	Enhances the sweetness and gives a creamy contrast.
Mini Marshmallows	Adds a chewy texture to complement the frosting.
Crushed Graham Crackers	Adds a slight crunch for texture balance.
Drizzle of Melted White Chocolate	Creates a glossy, bakery-style finish.

How to Frost the Blondies

1. Spread the Marshmallow Buttercream Evenly – Use an offset spatula or a butter knife to gently spread the frosting over the cooled blondies. Try to create a smooth layer.
2. Chill Before Cutting – For clean slices, place the frosted blondies in the refrigerator for 15-20 minutes to firm up.
3. Add Toppings Last – Sprinkle toppings right before serving so they stay crisp and fresh.

Best Ways to Cut and Serve Blondies

Cutting blondies can be tricky because of their soft and chewy texture. Follow these tips for neat, bakery-style slices:

✅ Use a Sharp Knife – A large chef’s knife works best.
✅ Wipe the Knife Between Cuts – Clean the blade with a damp cloth to get smooth edges.
✅ Cut into Even Squares – Use a ruler to mark even sections before slicing.
✅ Serve at Room Temperature – This keeps the frosting soft and creamy.

Serving Size Guide	Best for…
9 Large Squares	Decadent, bakery-style treats.
16 Smaller Squares	Bite-sized pieces for parties.
Rectangular Bars	Great for lunchboxes and on-the-go snacks.

Common Mistakes to Avoid When Making Blondies

Even though Cake Batter Blondies with Marshmallow Buttercream are simple to make, a few common mistakes can lead to blondies that are too dry, too cakey, or underbaked. Let’s go over some of these issues and how to fix them.

Why Do My Blondies Taste Like Cake?

Blondies are meant to be dense and chewy, not light and fluffy like cake. If your blondies turn out cakey, it could be due to:

🚫 Too Much Baking Powder or Baking Soda – A leavening agent can make blondies rise too much, creating a cake-like texture. Solution: Stick to the recipe’s recommended amount (usually ½ teaspoon of baking powder).

🚫 Overmixing the Batter – Overmixing incorporates too much air, leading to a lighter texture. Solution: Stir the batter just until combined—a few lumps are okay!

🚫 Using Too Much Flour – Extra flour absorbs moisture, making blondies drier. Solution: Spoon and level the flour when measuring instead of scooping directly from the bag.

Are Blondies Supposed to Be Gooey in the Middle?

Yes! Blondies should have a slightly gooey center when you take them out of the oven. However, if they seem too undercooked, here’s what might have gone wrong:

✅ Blondies Continue Baking in the Pan – They set as they cool, so don’t overbake them. If the edges are golden brown and the center has a few moist crumbs on a toothpick, they’re done!

✅ Baking at Too High a Temperature – This can cook the edges too fast while leaving the center raw. Solution: Keep the oven at 350°F (175°C) for even baking.

✅ Using a Dark Baking Pan – Dark pans absorb more heat, often overcooking blondies on the outside. Solution: Use a light-colored metal pan for better heat distribution.

Other Common Blondie Baking Mistakes

Mistake	Fix
Blondies are too dry	Reduce baking time by 2-3 minutes or add an extra egg yolk for moisture.
Blondies are too oily	Use melted butter, not oil for the best texture.
Blondies fall apart when cutting	Chill in the fridge for 15-20 minutes before slicing.
Sprinkles bled into the batter	Use jimmies (long sprinkles), not nonpareils (small round ones), which bleed color.

How to Store and Keep Blondies Fresh

Proper storage is key to keeping your Cake Batter Blondies with Marshmallow Buttercream fresh, soft, and delicious. Whether you want to enjoy them over a few days or save them for later, follow these tips for the best results.

Storing at Room Temperature vs. Refrigeration

Storage Method	Best For	Duration
Room Temperature	Best for soft, chewy blondies	Up to 3 days
Refrigeration	Keeps frosting firm & extends shelf life	Up to 1 week
Freezing	Long-term storage without losing texture	Up to 3 months

How to Store at Room Temperature

✅ Place blondies in an airtight container to prevent them from drying out.
✅ Store in a cool, dry place, away from direct sunlight.
✅ If stacking, place parchment paper between layers to keep the frosting intact.

How to Store in the Refrigerator

✅ Refrigeration is ideal if you want the marshmallow buttercream to stay firm.
✅ Use an airtight container to prevent the blondies from absorbing fridge odors.
✅ Before serving, let them come to room temperature for about 20-30 minutes to soften.

Freezing Tips for Long-Term Storage

If you want to make blondies ahead of time, freezing is a great option!

How to Freeze Blondies

1️⃣ Before Frosting: Wrap individual blondie squares tightly in plastic wrap, then place them in a freezer-safe bag or airtight container.
2️⃣ After Frosting: Place the frosted blondies in a single layer on a baking sheet and freeze for 1 hour. Once firm, wrap them individually in plastic wrap and store in an airtight container.

How to Thaw Blondies

• At Room Temperature: Let frozen blondies sit at room temp for 1-2 hours before serving.
• In the Fridge: Thaw overnight in the refrigerator for the best texture.

Fun Variations of Cake Batter Blondies

Want to switch things up? Try one of these creative variations:

1. Chocolate Chip Cake Batter Blondies

For an extra burst of sweetness, add chocolate chips to the batter.

2. Peanut Butter Swirl Blondies

If you’re a peanut butter fan, this variation adds a rich, nutty contrast to the sweet cake batter flavor.

3. Birthday Cake Blondies

Make these blondies extra festive by increasing the birthday cake flavor!

4. Cookies & Cream Blondies

Oreo lovers, this one’s for you! The combination of chewy blondies, marshmallow frosting, and crushed cookies is absolutely irresistible.

FAQ – Cake Batter Blondies

More Brownies and Blondies Recipes

Final Thoughts

Now that you know everything about making the best Cake Batter Blondies with Marshmallow Buttercream, it’s time to start baking! These blondies are:
✔ Easy to make with simple ingredients
✔ Chewy, buttery, and full of cake batter flavor
✔ Perfect for parties, birthdays, or a fun weekend treat

Looking for another rich, indulgent dessert? Check out these M&M’s Brownies for a colorful and delicious twist!