Birthday Cake Blondies

Name: Birthday Cake Blondies
Prep time: 15 min
Cook time: 25 min
Total time: 35 min
Ingredients: 3/4 Cup (170g |12 Tablespoons) Unsalted Butter, melted; 1 1/3 Cup (267g) Light or Dark Brown Sugar, packed; 1 Large Egg + 1 Yolk, room temp; 1 Tablespoon Clear Vanilla *see note below; 1 ½ Cups (190 grams) All-Purpose Flour; ½ Teaspoon Fine Sea Salt; Heaping 1/2 Cup (90g) White Chocolate Chips; 8 Golden Oreo Cookies, roughly chopped; 1/4 Cup Rainbow Sprinkles

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These soft and chewy Birthday Cake Blondies are loaded with golden Oreo cookie pieces, white chocolate chips and rainbow sprinkles! A nostalgic treat that's perfect for any occasion!

Why You Will Love These Cake Batter Blondies

Best texture! They are fudgy, gooey in the center, and crispy on the edges. Be sure to check out my White Chocolate and Raspberry Blondies and Brown Butter Oreo Blondies for more gooey blondies!
SO easy to make! You’ll only need a bowl and a whisk! There is no need to break out an electric mixer.
Less than 10 ingredients. You just need 9 simple ingredients to make these amazing Golden Oreo blondies!

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Why You Will Love These Cake Batter Blondies
Ingredient Notes
Step By Step Instructions
Substitutions
Variations
Equipment
Storage
Expert Tips
FAQ
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Ingredient Notes

Unsalted Butter – We'll be using melted butter to create a chewier blondie.
Brown Sugar – You can use light or dark brown sugar.
Egg + Yolk – The extra yolk also creates a chewy texture. Make sure your eggs are at room temperature. You can quickly bring them to temp by submerging into hot tap water for 15 minutes.
Clear Imitation Vanilla Extract– Clear vanilla gives these funfetti bars that authentic birthday cake flavor.
All-Purpose Flour – I love using King Arthur’s all-purpose flour.
Salt – Enhances flavors and balances the sweetness.
Golden Oreos – Golden Oreo cookie pieces are added to the batter and works so well with white chocolate.
White Chocolate – You can use white chocolate chips or chunks.
Rainbow Sprinkles - For best results, use rainbow sprinkles. Do not use nonpareils, as they bleed.

*See recipe card for quantities.

Step By Step Instructions

Here are step-by-step photos and instructions on how to make these Funfetti Birthday Blondies! Please find the detailed instructions in the recipe card at the end of this post.

Melted butter and brown sugar in a glass mixing bowl

Step 1. Combine Wet Ingredients - In a large bowl, whisk together melted butter and brown sugar.

Egg, yolk and clear vanilla added to butter, brown sugar mixture

Step 2. Add egg, yolk and clear vanilla extract.

Butter, sugar, egg, yolk, vanilla mixture in glass bowl with whisk

Step 3. Whisk until light and fluffy; about 2 minutes.

Step 4. Combine Dry Ingredients - Sift in all-purpose flour and salt into the wet ingredients.

Crushed golden Oreos, sprinkles and white chocolate chips added to batter

Step 5. Add chopped golden Oreos, white chocolate chips and sprinkles. Mix until just incorporated.

Step 6. Bake and Serve - Transfer the cookie dough batter to an 8x8 inch (20×20 cm) pan. Bake at 350ºF (180ºC) for about 25 minutes. Cool, slice and enjoy!

Hint: To get clean slices, make sure your blondies are completely cooled! Slice into the blondies and wipe down your knife after each cut.

Substitutions

For the Clear Vanilla – If you do not have clear vanilla, you can also use real vanilla extract. You can even use almond extract.
For the Brown Sugar – You can use light or dark brown sugar.
For the Chocolate Chips – If you are not a fan of white chocolate, feel free to use semi-sweet or dark chocolate. You can use chips, chunks or chopped chocolate.
For the Sprinkles - Rainbow jimmies or confetti sprinkles are best to use in this blondie recipe as they don't bleed into the batter. Just don't use nonpareils as they will bleed.

Variations

Chocolate Oreo Blondies – For a different take on these blondies, try my Brown Butter Oreo Blondies!
Gluten-free – Use gluten-free Oreos and a 1-to-1 cup gluten-free flour blend.

Equipment

Square Baking Pan – 8×8 inch (20×20 cm)

Storage

Room Temperature -Store in an airtight container on the counter for 3 to 4 days!
Refrigerator – Store in an airtight container for about 1 week. You can either allow it to come to room temperature before serving or eat it straight out of the fridge.
Freezer – Store the cooled pieces of blondies in a freezer bag for up to 2 months. Just thaw overnight in the fridge and then eat cold or allow to come to room temperature before serving.

Expert Tips

Measure your flour correctly. When measuring flour, aerate the flour first, then scoop into your measuring cup and then level off with the back of a butter knife. Packing the flour will add too much flour and can result in a drier blondie. However, I recommend using a kitchen scale to measure your ingredients as it’s the most accurate. You can refer to King Arthur’s Weight Chart for conversions.

Do not overmix. When combining your flour, mix until there are very few flour streaks left. Overmixing will cause the gluten in the dough to overdevelop.

Do not overbake. Your baking time can vary depending on your oven. We want these blondies to be soft and gooey so err on the side of underbaking them slightly. It’s ready when the edges are golden brown and is middle is set and not jiggly.

Bake in a metal pan. For best results, bake in a metal pan, not glass.

Line your pan with parchment paper. For easy removal, don’t forget to line your baking pan.

Cool completely before serving. For clean slices, allow to cool completely before cutting into it.

FAQ

What is clear vanilla?

According to Goodness Vanilla, clear vanilla extract is made with a synthetic vanillin. It's made to taste like u0022real vanillau0022 and is a clear liquid. It's often used in desserts when you want to keep it bright white, such as meringue, white cake or white frosting.

What are Blondies?

Blondies are occasionally referred to as “blonde brownies”. In place of cocoa powder, vanilla and brown sugar are the main flavor profile for blondies.

Can I bake them in a 9×9 inch pan?

You can, however, they will be much flatter! I have not tested them in a 9×9 inch (22x22 cm) pan, but I’d keep an eye on them as they won't take as long to bake.

Can I make these gluten-free?

Yes! Use gluten-free cookies and a 1-to-1 cup gluten-free flour blend.

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