These Cake Batter Blondies are a celebratory treat that combines the nostalgic flavor of a birthday cake with the dense, chewy texture of a perfect blondie. They are incredibly easy to whip up using a boxed cake mix, making them a go-to recipe for last-minute gatherings, school treats, or whenever you need a colorful pick-me-up.
Packed with rainbow sprinkles and sweet white chocolate chips, these bars offer a “funfetti” experience in a rich, fudgy format that both kids and adults will adore.
Recipe Details
- Flavor Profile: Sweet and buttery with the distinct, nostalgic taste of vanilla cake batter and white chocolate.
- Textures: Dense, chewy, and soft with a slight crunch from the sprinkles and white chocolate chips.
- Total Time: Approximately 5–10 minutes of prep and 25–30 minutes of baking, plus cooling time.
- Difficulty Level: Very Easy. This one-bowl recipe is perfect for beginners and requires minimal kitchen equipment.
What You’ll Need
To create these festive bars, you will need a standard box of yellow or vanilla cake mix, which serves as the flavored flour base. The moisture and structure are provided by vegetable oil, a large egg, and a bit of whole milk. To turn them into true “cake batter” blondies, you will fold in a generous amount of rainbow sprinkles and white chocolate chips for extra sweetness and texture.
Ingredient Notes
- Dry Cake Mix – Use a standard 13.25-ounce box. Do not follow the instructions on the box; you only need the dry powder for this recipe.
- Whole Milk – Using whole milk instead of water adds a richness that helps the blondies maintain their fudgy, dense consistency.
- White Chocolate Chips – These complement the vanilla cake flavor perfectly and add pockets of creamy sweetness throughout the bars.
- Rainbow Sprinkles – “Jimmies” (the rod-shaped sprinkles) work best here as they hold their color during baking better than nonpareils.
- Vegetable Oil – This ensures the blondies stay moist and soft for a full week of storage.
Add-ins and Substitutions
- Chocolate Swap: If you prefer, you can use milk chocolate or semi-sweet chocolate chips instead of white chocolate for a “marble cake” vibe.
- Cake Mix Flavors: While vanilla and yellow are classic, you can try this method with strawberry or lemon cake mix for a fruity twist.
- Nutty Crunch: Fold in 1/2 cup of chopped macadamia nuts or walnuts to add a savory element to the sweet bars.
How to Make Cake Batter Blondies
The process for these blondies is incredibly simple, relying on a thick batter that yields a dense, non-cakey result.
Start by preheating your oven to 350F (177C) and lining an 11×7-inch baking pan with parchment paper. In a large bowl, combine the dry cake mix, oil, egg, and milk. Use a silicone spatula to mix them together; the batter will be extremely thick, which is exactly what you want for a blondie texture. Fold in the rainbow sprinkles and white chocolate chips until evenly distributed.
Spread the thick dough into your prepared pan, using the spatula to press it into the corners. If you like, you can add a few extra sprinkles on top for a pop of color. Bake for 25–30 minutes until the edges are lightly browned. The center will still look soft, but it will set as it cools. Allow the bars to cool in the pan for 30 minutes before lifting them out and slicing.
Pro Tip: Resist the urge to keep these in the oven until the center looks “done.” The secret to a fudgy blondie is pulling them out while the center is still soft; they will finish setting up during the 30-minute cooling period on the wire rack.
Recipe Tips
- Parchment Sling: Leaving an overhang of parchment paper on the sides makes it much easier to lift the entire block of blondies out for clean, square cuts.
- Room Temperature Ingredients: Ensure your egg and milk are at room temperature to help them incorporate smoothly into the thick dry mix.
- Batter Spreading: Since the batter is so thick, you can lightly grease your spatula or use your hands (lightly dampened) to press the dough into an even layer in the pan.
- Don’t Over-mix: Mix just until the flour disappear to keep the texture tender and avoid a gummy result.
FAQs
Can I use a 9×9 inch pan? Yes, you can use a 9×9 inch pan, but the blondies will be slightly thicker and may require an extra 2–4 minutes of baking time.
My blondies are more like cake than bars. What happened? This usually happens if you over-mix the batter or if the egg was particularly large. Ensure you are using the exact amount of milk and oil specified to keep them dense.
Can I use nonpareils (the tiny balls) instead of jimmies? You can, but be aware that nonpareils tend to “bleed” their color into the batter more than jimmies, which might turn your blondies a slightly grey or muddy color.
Serving Suggestions
- Ice Cream Sandwich: Use two blondies to sandwich a scoop of vanilla or birthday cake ice cream for an epic dessert.
- Buttercream Topping: If you want to go full birthday cake, you can spread a thin layer of vanilla frosting over the cooled bars before slicing.
- Warm with Milk: These bars are very sweet and rich, making them the perfect companion for a cold glass of milk.
Make This Recipe in Advance
These blondies are perfect for making ahead of time because they stay moist for up to a week. You can bake them 1–2 days before you need them and store them in an airtight container at room temperature. They also freeze remarkably well; simply wrap individual squares in plastic wrap and store them in a freezer-safe bag for up to 3 months.
Print
Easy Fudgy Cake Batter Funfetti Blondies
- Total Time: 40 minutes
- Yield: 15–18 Bars 1x
- Diet: Vegetarian
Description
A celebratory treat combining nostalgic birthday cake flavor with a dense, chewy blondie texture. Using a boxed cake mix for a quick shortcut, these fudgy bars are packed with rainbow sprinkles and white chocolate chips for a rich funfetti experience.
Ingredients
The Batter
- 1 (13.25-oz) box yellow or vanilla cake mix
- 1/4 cup vegetable oil
- 6 tbsp whole milk (room temp)
- 1 large egg (room temp)
The Mix-ins
- 1/2 cup rainbow ‘jimmie’ sprinkles
- 1/2 cup white chocolate chips
Instructions
Prep: Preheat oven to 350°F. Line an 11×7 pan with parchment.
Mix: Combine dry cake mix, oil, egg, and milk. Stir until well combined (batter will be very thick).
Fold: Gently stir in sprinkles and white chocolate chips.
Spread: Press the heavy batter into the pan and smooth the surface.
Bake: Bake for 25–30 mins. Pull when edges are brown but center is soft. Cool for 30 mins to firm up.
Notes
The ‘Jimmies’ Rule: Use rod-shaped sprinkles to prevent color bleeding; nonpareils will turn the batter grey.
Don’t Overbake: Pull the pan while the center still has a slight jiggle to ensure a fudgy, not dry, texture.
Handling Thick Batter: Lightly dampening your hands helps press the sticky dough into the corners without it sticking to you.
- Prep Time: 10 minutes
- Cook Time: 30 minutes
- Category: Dessert / Snack Bars
- Method: One-Bowl / Baking
- Cuisine: American Funfetti Inspired
Nutrition
- Serving Size: 1 Bar
- Calories: 210
- Sugar: 18
- Sodium: 240
- Fat: 9
- Saturated Fat: 3
- Unsaturated Fat: 6
- Trans Fat: 0
- Carbohydrates: 31
- Fiber: 0.5
- Protein: 2
- Cholesterol: 15
Keywords: cake batter blondies, funfetti dessert bars, easy cake mix recipes, white chocolate sprinkle bars, birthday cake blondies
