Name: Easy Homemade Birthday Cake Blondies (45 minutes)
Prep time: 15 min
Cook time: 28 min
Total time: 43 min
Yield: 16
Ingredients: 175 g (1 1/4 cups) all-purpose flour; 1 teaspoon baking powder; 1/2 teaspoon salt; 113 g (1/2 cup) unsalted butter, melted; 165 g (3/4 cup) light brown sugar; 55 g (1/4 cup) granulated sugar; 1 large egg, at room temperature; 1 large egg yolk, at room temperature; 2 teaspoons pure vanilla extract; 150 g (3/4 cup) white chocolate chips; 40 g (1/4 cup) sprinkles; 4-5 Gold Oreo Cookies, roughly chopped or broken

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Celebrate any occasion with these gooey Birthday Cake Blondies! Packed with white chocolate chips, sprinkles, and Golden Oreos, they’re soft, chewy, and impossible to resist!

Overhead shot of squares of birthday cake blondies with white chocolate chips and rainbow sprinkles.

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Craving something sweet, nostalgic, and easy to make? These birthday cake blondies are your new go-to! Loaded with chunks of Golden Oreos, rainbow sprinkles, and white chocolate chips, they’re everything you love about a classic birthday cake, but in a soft, chewy blondie form. The best part? They’re ready in just 45 minutes, making them perfect for busy bakers who want a quick, crowd-pleasing dessert.

If you’re in celebration mode, pair these cake blondies with birthday cupcakes for the ultimate dessert table, or try them with stuffed birthday cookies for another fun twist on classic birthday cake flavor.

What are blondies?

Blondies are like the vanilla-loving cousin of brownies–rich, chewy, and totally indulgent, but with a warm, buttery vanilla flavor instead of chocolate. While they might look similar to cookie bars, blondies are their own delicious category. Unlike cookie bars, which tend to have a firmer, cookie-like texture, blondies have that signature fudgy consistency we all love in brownies (with the help of light brown sugar). Think gooey, soft crumb, and just a little bit dense in the best way possible.

Ingredient Notes

Butter. We’re using melted butter for the perfect chewy texture. I always use unsalted butter to control the amount of salt in my recipes. If you have salted butter, reduce the salt to ¼ teaspoon.
Eggs. Set your eggs out for about 1 hour to bring to room temperature. You can quicken the process by setting them in a bowl of warm water for 10 minutes.
Vanilla. For the best flavor, I use good-quality vanilla. For a bonus flavor, you can substitute ½ teaspoon of the vanilla with almond extract.
White chocolate. We’re using white chocolate chips for this recipe. You can substitute them with what I prefer to use, chopped white chocolate or even semi-sweet chocolate.
Sprinkles. Rainbow colored ones are so fun! I suggest sticking with sprinkles. Nonpareils are fun too, but they can bleed into your batter during baking.
Golden Oreos. Any vanilla cookie sandwich can be used in place of the golden Oreos. If you prefer, use traditional Oreos or chocolate cookie sandwiches!

Please see the recipe card below for the full list of ingredients and measurements!

What Pan Sizes Can You Use?

This recipe is for an 8x8-inch pan, which gives you thick, chewy birthday blondies with that perfect gooey center. But don’t worry if you don’t have one! You can use a 9x9-inch pan instead–just know the blondies will be a bit thinner, so keep an eye on the bake time as they may cook slightly faster.

If you’re feeding a crow (or just want more blondies, because why not?), double the recipe and bake it in a 9x13-inch pan. You’ll get a bigger batch of equally delicious, slightly thinner blondies perfect for sharing as a blondie cake

Step-By-Step Instructions

Whisked flour, baking powder and salt in a mixing bowl.

Combine dry ingredients. Give the flour, baking powder, and salt a good whisk.

Whisked melted butter and granulated sugar in a mixing bowl.

Combine butter and sugar. In a separate bowl, whisk together until smooth.

Whisked melted butter, eggs, and granulated sugar in a mixing bowl.

Combine wet ingredients. Add the eggs and vanilla to the butter and sugar mixture and whisk vigorously for 1 minute.

Birthday cake blondie batter in a mixing bowl.

Add dry ingredients. You want to gently fold the dry ingredients into the wet ingredients until mostly combined. It’s okay to see a few streaks of flour.

Mixing bowl of birthday cake blondie batter with sprinkles and white chocolate chips on top.

Add mix-ins. Fold in the sprinkles and white chocolate chips until evenly spread throughout the batter.

Pan of unbaked birthday cake blondies topped with broken golden oreos.

Spread and bake. In the prepared pan, spread the batter into an even layer using a small offset spatula or knife. Gently press the broken Oreos into the top of the batter. Bake for 25-28 minutes until the edges of the blondies begin to pull away from the pan.

Pro Tip: To keep their shape, allow these birthday cake blondies to cool completely before slicing. You can also chill the blondies in the fridge to firm the butter more quickly.

How to Know When Blondies Are Done Baking

Knowing when to pull your birthday cake blondies out of the oven is key! Take them out too early, and they’ll be raw in the middle; too late, and they’ll turn dry and cakey. The sweet spot? A toothpick should come out with a few gooey crumbs or clean but not coated in raw batter. They should look and feel slightly underdone–don’t worry, the residual heat will finish the job, leaving you with perfectly fudgy, tender blondies.

Expert Tips

Use a light-colored pan: A light-colored metal pan ensures even baking, giving your blondies that golden, chewy perfection. Dark, coated pans can heat unevenly, making the edges overbake while the center stays underdone.
Line your pan with parchment paper: Trust me, this step is a game-changer. Not only does it make cleanup a breeze, but it also makes removing your blondies so much easier. Just lift the parchment out of the pan, and voila–perfectly intact blondies every time.
Mix for a shiny crust: Want that gorgeous, crackly top? It’s all about aerating the batter! Whisk the sugar and eggs until they’re pale and fluffy before adding the rest of the ingredients. This simple step makes a huge difference.
Don’t overmix the batter: Once you add the dry ingredients, mix just until everything is combined. Overmixing can lead to tough blondies, and no one wants that! Keep it gentle for a soft, tender crumb.

Cut birthday cake blondies stacked in a pile with white chocolate chips in the background.

Storage & Freezing

Room temperature: Keep your birthday blondies fresh and chewy by storing them in an airtight container at room temp for up to 3 days. Perfect for when you know they’ll be gone in no time (because, let’s be real, they will).

Refrigerate: Want to make them last a little longer? Pop them in the fridge for up to 1 week. Just let them come to room temp or give them a quick zap in the microwave before serving to bring back that soft, gooey texture.

Freeze: These blondies freeze like a dream! Wrap them tightly in plastic wrap, then place them in a freezer-safe bag or container. They’ll stay fresh for up to 3 months. When you’re ready to indulge, let them thaw at room temp or warm them up for a freshly-baked taste.

Birthday cake blondies cut into square with one missing a bit out of it and milk in the background.Birthday cake blondies cut into square with one missing a bit out of it and milk in the background.

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