Best Kid-Approved Birthday Cake Blondies Recipe
These birthday cake blondies are chewy, buttery bars made with yellow cake mix and rainbow sprinkles. They come together in under 10 minutes and are perfect for bake sales, birthday parties, or any celebration.
- Prep Time: 10 minutes
- Cook Time: 25 minutes
- Total Time: 35 minutes
- Yield: 16 servings 1x
- Category: Dessert
- Cuisine: American
Ingredients
Scale
- 1 box yellow cake mix (15.25 oz)
- 1/2 cup unsalted butter, melted
- 1 large egg
- 1 teaspoon vanilla extract
- 1/2 cup rainbow sprinkles (jimmies, not nonpareils)
- 1/4 cup white chocolate chips (optional)
- 1/4 cup mini chocolate chips (optional)
- 1/2 teaspoon almond extract (optional)
Instructions
- Preheat your oven to 350°F (175°C). Line your 8×8 pan with parchment paper, leaving some overhang on two opposite sides.
- Melt the butter in a microwave-safe bowl in 20-second intervals until fully melted. Let it cool for a couple minutes.
- In a mixing bowl, whisk together the melted butter, 1 large egg, and 1 teaspoon vanilla extract until smooth and well combined, about 30 seconds.
- Pour the entire box of yellow cake mix into the bowl. Stir with a wooden spoon or spatula until just combined. Do not overmix.
- Gently fold in 1/2 cup rainbow jimmies using a spatula until evenly distributed. The batter will be thick and slightly sticky.
- Scrape the batter into the prepared pan and spread it evenly using the back of a spatula or lightly greased fingers.
- Bake for 20-25 minutes. At 20 minutes, check for doneness: edges should be golden brown and pulling away from the pan, center should still look slightly soft. A toothpick inserted in the center should come out with a few moist crumbs.
- Cool in the pan on a wire rack for at least 30 minutes. Then use the parchment handles to lift the slab out and cool completely on the rack before cutting.
- Cut into 16 squares using a sharp knife, wiping the knife clean between each slice.
Notes
Don’t overbake; blondies continue to set as they cool. Use jimmies (long sprinkles) not nonpareils to avoid color bleeding. Cool completely before cutting for clean edges. For gluten-free, use a gluten-free yellow cake mix. For dairy-free, use plant-based butter.
Nutrition
- Serving Size: 1 blondie
- Calories: 190
- Sugar: 15
- Sodium: 240
- Fat: 9
- Saturated Fat: 5
- Carbohydrates: 26
- Protein: 2
Keywords: birthday cake blondies, cake mix blondies, easy dessert, kid-friendly, bake sale, sprinkles, quick dessert