Cake Batter Blondies are my go-to when I want a bar cookie that’s soft and chewy with that familiar yellow cake flavor. They’re simple, sweet, and full of white chocolate in a way that still feels like a classic blondie.
The texture is what sells me: thick, a little dense, and chewy in the center with edges that set up nicely. The sprinkles add a little crunch and that birthday-cake look without making the whole thing taste like frosting.
I like these for bake sales, cookie trays, and any time I need a dessert that slices cleanly and travels well. They’re also great when you want something fun but don’t want to deal with chilling dough or rolling cookies.
Why You’ll Love This Recipe
Soft and Chewy: These bake up with that thick, chewy center that makes blondies worth it. They’re especially good once they’ve cooled completely.
One Bowl: Everything comes together fast with minimal dishes. I usually just whisk the wet ingredients, stir in the mix, and I’m done.
Classic Cake Batter Flavor: Using yellow cake mix gives you that familiar “cake batter” taste without extra steps. It’s sweet, buttery, and very straightforward.
Sprinkles Make It Easy to Dress Up: A handful of rainbow sprinkles makes the bars look special right away. I like saving a little for the top so you actually see them after baking.
Easy to Customize: Swap the chips, swap the sprinkles, or do both. It’s a flexible base when you want to use what you already have.
Ingredients You’ll Need
Batter
- Yellow cake mix: I use a regular boxed yellow cake mix here, and it’s what gives these that classic cake-batter flavor. Any standard brand works fine.
- Egg: This helps the bars hold together and gives the batter structure so they slice neatly.
- Egg yolk: Don’t skip it if you can help it. The extra yolk is a big part of the chewy, rich texture.
- Vanilla extract: Simple, but it makes the “cake batter” flavor taste more like the real thing.
- Unsalted butter: Melted butter keeps the batter easy to stir and gives you a denser, chewier bar than using softened butter. Let it cool slightly so it doesn’t cook the eggs.
- Milk: Just enough to smooth out the batter since cake mix can be a little dry. Any milk you keep around is fine.
- Fine salt: A small amount makes the white chocolate and cake flavor taste less flat. I use fine salt so it mixes in evenly.
Mix ins
- White chocolate chips: I like white chocolate here because it leans into the birthday-cake flavor. If you only have milk or semi-sweet chips, those work too.
- Rainbow sprinkles: Use the classic jimmies style if you can; they hold up better in the batter. I also like a little extra on top for looks.
Recipe Instructions
- Preheat the oven: Heat the oven to 350°F.
- Prepare the pan: Line an 8-inch square baking pan with parchment paper, then lightly grease it.
- Whisk the wet ingredients: In a large bowl, whisk the melted butter, egg, egg yolk, vanilla, and milk until smooth.
- Add the dry ingredients: Add the cake mix and salt, then stir just until you no longer see dry streaks. The batter will be thick.
- Fold in the mix-ins: Fold in the white chocolate chips and sprinkles, saving a little of each to sprinkle on top.
- Spread the batter: Scrape the batter into the prepared pan and spread it into an even layer. Sprinkle the reserved chips and sprinkles over the surface.
- Bake: Bake for 20 to 25 minutes, until the edges are set and lightly golden and a toothpick in the center comes out with a few moist crumbs.
- Cool and slice: Cool completely in the pan, then lift out using the parchment and slice into bars.
Some of my tips!
This is the part that really makes a difference. If you only read one section, make it this one because this is where I share the little trick that helps the recipe turn out so well.
Recipe Tips & Tricks
Don’t overmix once the cake mix goes in. Stir just until the batter comes together and you don’t see dry patches. Overmixing tends to make the bars bake up tougher.
Let the melted butter cool a bit. Warm is fine, hot is not. If it’s very hot, it can tighten up the batter and scramble the eggs before you even get to baking.
Pull them when the center still looks a little soft. If you want extra chewy blondies, underbake slightly and let them finish setting as they cool. A toothpick with a few moist crumbs is what you’re after.
Cool all the way before slicing. These are hard to cut cleanly when they’re warm. Once they’re fully cool, you’ll get neat squares and the texture is better.
Save some chips and sprinkles for the top. It’s a small thing, but it makes a big difference in how they look after baking. The bars are prettier and you can tell what’s inside.
Make some touches!
There are plenty of easy ways to serve this depending on the occasion. Keep it simple, or add a few small touches to make it feel a little more special.
Serving Suggestions
- Milk: A cold glass of milk is classic with these. I like it especially when the bars are on the chewy side.
- Coffee or espresso: These are sweet, so coffee is a nice balance. I usually do plain black coffee or a latte.
- Ice cream: Serve a bar with vanilla ice cream on the side if you want a more “dessert-dessert” plate. A drizzle of chocolate sauce is nice, but not required.
- Fruit: Fresh berries are great here, especially strawberries or raspberries. It keeps the plate from feeling too heavy.
Save it for later
This section covers how to store leftovers and what parts of the recipe you can prepare ahead of time.
Storage and Make Ahead
Store the blondies airtight at room temperature for up to 4 days. I keep them in a container with a tight lid so the edges don’t dry out. If you stacked them, a piece of parchment between layers helps.
If you want to make them ahead, bake and cool them completely, then cut and store. They slice more cleanly once they’ve had time to fully set.
For longer storage, freeze the bars (whole or sliced) for up to 2 months. Thaw at room temperature, or in the fridge overnight if you prefer.
A few quick answers
This section covers a few extra details that may help before you head to the recipe card.
Recipe FAQs
How do I know when cake batter blondies are done?
I look for set, lightly golden edges and a center that doesn’t jiggle. A toothpick in the middle should come out with a few moist crumbs, not wet batter.
If you bake until the toothpick is totally clean, the bars usually end up more cakey and less chewy.
Can I use a 9-inch pan instead of an 8-inch pan?
You can, but the blondies will be thinner and will bake faster. Start checking a few minutes early and pull them as soon as the edges are set and the middle gives you moist crumbs.
Can I swap the white chocolate chips or the sprinkles?
Yes. Milk chocolate chips work well, and mini chocolate chips are a good swap for sprinkles if you want less crunch and less color.
Can I make these gluten-free?
Use a gluten-free yellow cake mix. If your batter looks dry or crumbly (some gluten-free mixes run that way), add a splash more milk until it turns into a thick, spreadable batter.
Why are my blondies crumbly instead of chewy?
Most of the time it’s from baking a little too long or not measuring the wet ingredients correctly (especially the butter and eggs). Another thing that helps is letting them cool completely before slicing, since they firm up as they sit.
You might also like
Before you go, take a look at a few other recipes below the recipe card. They use similar ingredients in a different way and are worth saving too.
MORE DINNER RECIPES TO TRY
Cake Batter Blondies
INGREDIENTS
Batter
- 1 box yellow cake mix 15.25 oz
- 1 large egg
- 1 large egg yolk
- 1 tsp vanilla extract
- 1 2 cup unsalted butter melted and cooled slightly
- 2 tbsp milk
- 1 4 tsp fine salt.
Mix ins
- 3 4 cup white chocolate chips
- 1 3 cup rainbow sprinkles plus extra for topping.
INSTRUCTIONS
Prep
- preheat oven to 350 F
- line an 8 inch square baking pan with parchment and lightly grease.
Mix and bake
- whisk melted butter egg egg yolk vanilla and milk until smooth
- add cake mix and salt and stir just until combined into a thick batter
- fold in white chocolate chips and sprinkles reserving a little of each for the top
- spread batter evenly in pan and sprinkle remaining chips and sprinkles over surface
- bake until edges are set and lightly golden and a toothpick inserted in the center comes out with a few moist crumbs 20 to 25 minutes
- cool completely in pan then lift out and slice.
