Cake Mix Sprinkle Blondies are my go-to when I want a soft and chewy bar that’s more interesting than plain blondies, but still simple. They taste like birthday cake in bar form, with that buttery vanilla base and little pops of sweetness from the sprinkles.
I like this version because the texture stays thick and fudgy in the middle, with set edges that slice clean once they’re fully cool. The optional white chocolate chips make them a little richer, but I make them both ways depending on what I have.
These are especially good for cookie trays, bake sales, and any time you need a quick dessert bar that looks cheerful without extra decorating. I usually serve them as-is, or with something cold like milk or coffee on the side.
Why You’ll Love This Recipe
Fast and Easy: One bowl, no mixer, and it goes from pantry to oven quickly. It’s the kind of recipe I make when I need dessert without a big plan.
Soft and Chewy: The centers stay chewy as long as you pull them when they’re just set. I’d much rather have these slightly underbaked than dry.
Fun to Share: The sprinkles make them look festive right away. They’re great for birthday parties, class treats, and cookie trays.
White Chocolate Option: You can keep them simple with just sprinkles, or add white chips for a sweeter, richer bar. Both versions work.
Reliable Recipe: Cake mix makes the base consistent and forgiving. Even if you’re not a big baker, these usually come out the way you want.
Ingredients You’ll Need
Batter
- Yellow or white cake mix: Either one works, so I use whatever is in the pantry. Yellow gives a slightly richer “birthday cake” flavor, and white tastes a little lighter.
- Unsalted butter: Melted butter is what gives these bars that buttery blondie taste. Let it cool a bit so it doesn’t scramble the eggs when you whisk.
- Eggs: Eggs bind everything and help the blondies set while staying chewy. Use large eggs if you can.
- Vanilla extract: This is the main flavor booster, so don’t skip it. I use regular pure vanilla, but imitation is fine here too.
- Milk: A small splash loosens the batter just enough so it mixes smoothly. Any milk you have is fine.
Mix ins
- Rainbow sprinkles: I like classic jimmies for this because they hold their color a little better. Fold them in gently so the batter doesn’t turn grayish.
- White chocolate chips: Totally optional, but really good if you want the bars a little sweeter. If your chips are big, I sometimes use minis so they distribute more evenly.
- Salt: A small pinch helps cut the sweetness, especially if you add white chocolate chips. It’s optional, but I usually add it.
Recipe Instructions
- Preheat the oven: Heat the oven to 350°F. Line an 8×8-inch or 9×9-inch pan with parchment paper and lightly grease it.
- Whisk the wet ingredients: In a large bowl, whisk the melted (slightly cooled) butter, eggs, vanilla extract, and milk until smooth.
- Add the cake mix: Fold in the cake mix until a thick dough forms and you don’t see any dry streaks.
- Fold in the mix-ins: Gently fold in the rainbow sprinkles and the white chocolate chips (if using). Add a pinch of salt if you like.
- Press into the pan: Press the batter evenly into the prepared pan, then sprinkle a little extra sprinkles over the top.
- Bake: Bake for 20 to 26 minutes, until the edges are set and lightly golden and the center is just set.
- Cool: Cool in the pan for at least 30 minutes, then lift out using the parchment and cool completely before slicing for clean 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 overbake. Pull them when the edges look set and the center looks just set, even if it seems a little soft. They finish as they cool, and that’s what keeps them chewy.
Use parchment paper. It makes it much easier to lift the blondies out in one piece. It also helps you cool them faster and slice them more neatly.
Stir sprinkles in gently. If you mix too hard, the colors can bleed into the dough. A gentle fold is enough to spread them out.
Pick your pan based on thickness. I use an 8×8-inch pan when I want thicker bars. If you go with a bigger pan for thinner blondies, keep an eye on the bake time since they’ll finish sooner.
Cool completely before slicing. Warm blondies will stick to the knife and crumble a bit. Once they’re fully cool, you’ll get clean squares.
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. It’s especially nice if you added white chocolate chips.
- Coffee: I like these with plain hot coffee or an iced latte. The vanilla-sprinkle flavor goes really well with coffee.
- Ice cream: Serve a square with vanilla ice cream on the side if you want a more “dessert plate” feel. Let the blondie sit at room temp for a few minutes first if it’s been chilled.
- Fruit: Fresh berries are a good simple side, especially strawberries or raspberries. It’s a nice contrast to the sweet bars.
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 them airtight at room temperature and they stay soft for a few days. I like to put a piece of parchment between layers if I’m stacking them.
If you want to make this recipe ahead, bake the blondies the day before and leave them whole until you’re ready to serve. They slice cleaner once they’ve had time to cool and set.
For longer storage, you can freeze individual portions or freeze the whole slab wrapped well. Let them 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
Can I use yellow cake mix or white cake mix?
Yes, either one works. Yellow cake mix tastes a little more buttery, and white cake mix is a bit lighter, but the texture comes out very similar.
How do I know when the blondies are done?
Look for edges that are set and lightly golden, and a center that looks just set (not wet). If you wait for the center to look completely firm, they usually end up overbaked and less chewy.
Why did my sprinkles bleed color into the batter?
This usually happens from stirring too much, or from using sprinkles that bleed more easily. Fold them in gently at the end, and try jimmies instead of nonpareils if you want cleaner color.
Can I make these dairy-free?
Yes. Use a dairy-free butter substitute and dairy-free white chocolate chips (or skip the chips), and use your favorite non-dairy milk.
What pan size should I use?
An 8×8-inch pan gives you thicker blondies. A 9×9-inch pan works too, and if you use a larger pan for thinner bars, start checking a little early since they bake faster.
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 Mix Sprinkle Blondies
INGREDIENTS
Batter
- 1 box yellow or white cake mix 15.25 oz
- 1/2 cup unsalted butter melted and slightly cooled
- 2 large eggs
- 1 tsp vanilla extract
- 2 tbsp milk.
Mix ins
- 1/2 cup rainbow sprinkles plus extra for topping
- 1/2 cup white chocolate chips optional
- pinch of salt optional.
INSTRUCTIONS
Pan and mix
- Heat oven to 350 F
- line an 8x8 inch or 9x9 inch pan with parchment and lightly grease
- whisk melted butter eggs vanilla and milk until smooth
- fold in cake mix until a thick dough forms and no dry streaks remain
- fold in sprinkles and optional white chocolate chips.
Bake and cool
- Press batter evenly into prepared pan and top with extra sprinkles
- bake until edges are set and lightly golden and the center is just set 20 to 26 minutes
- cool in pan at least 30 minutes then lift out and cool completely before slicing for clean bars.
