Cake Mix Sprinkle Brownies are my go-to when I want chewy, fudgy brownies but I don’t want to babysit a long ingredient list. They’re rich and chocolatey like a classic boxed brownie, with rainbow sprinkles baked right in.
I like this version because the brownies stay soft in the middle with set edges, and the sprinkles give little pops of color without changing the flavor much. If you add the chocolate chips, it leans even more into that deep fudge brownie thing (which I’m always happy about).
These are especially good for birthday desserts, classroom treats, or a cookie tray when you want something bright and simple. I usually slice them small, since they’re pretty rich, and they stack well for sharing.
Why You’ll Love This Recipe
Fast and easy: It’s a one-bowl situation with a boxed mix, so you can have brownies in the oven quickly.
Soft and chewy: These bake up fudgy with that slightly chewy bite I want in a brownie bar.
Sprinkle look: The rainbow sprinkles make them look festive with almost no effort, especially with a sprinkle layer on top.
Reliable for parties: A 9×13 pan gives you plenty of squares, and they’re easy to transport and serve.
Easy to tweak: Add chocolate chips, swap in melted butter, or sneak in espresso powder if you like a deeper chocolate flavor.
Ingredients You’ll Need
Brownie Batter
- Fudge brownie mix: I use the standard 18 to 19 oz box. Any “fudge” style mix works well here and gives you that thicker, richer brownie texture.
- Eggs: Regular large eggs are what you want. They help the brownies set up while keeping the center soft.
- Vegetable oil: This keeps the brownies moist and chewy. If you want a richer flavor, melted butter works too.
- Water: Just enough to loosen the batter so it spreads evenly in the pan.
- Vanilla extract: A small thing, but it makes boxed mix taste more like homemade to me.
- Rainbow sprinkles: I strongly prefer rainbow jimmies here. Nonpareils tend to bleed more and can muddy the batter.
- Semi-sweet chocolate chips (optional): Semi-sweet is my go-to. Milk chocolate works if that’s what you have, but it will make the brownies sweeter.
Pan And Topping
- Nonstick cooking spray or softened butter: Use whatever you normally use for brownies. Don’t skimp on the corners.
- Parchment paper (optional): I like it for clean lifting and easy slicing, but it’s not required.
- Rainbow sprinkles: These are for the top, and they make the baked brownies look finished without frosting.
Recipe Instructions
- Preheat the oven: Heat the oven to 350°F.
- Prep the pan: Grease a 9×13-inch baking pan with nonstick spray or softened butter. Line with parchment paper if you want easy removal.
- Mix the wet ingredients: In a large bowl, whisk the eggs, vegetable oil, water, and vanilla until combined.
- Add the brownie mix: Add the boxed brownie mix and stir just until you don’t see dry streaks.
- Fold in the add-ins: Fold in the rainbow sprinkles and the chocolate chips, if using.
- Spread the batter: Scrape the batter into the pan and spread it evenly to the edges.
- Add the topping: Sprinkle rainbow sprinkles over the top of the batter.
- Bake: Bake for 23 to 28 minutes, until the edges are set and a toothpick in the center comes out with moist crumbs.
- Let cool: Cool in the pan for at least 30 minutes before slicing so you get clean squares.
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
Use rainbow jimmies. They keep their color better and don’t bleed as much into the batter. Nonpareils can turn the batter a little streaky.
Don’t overmix the batter. Stir just until the mix disappears. Overmixing is where brownies start to get more cake-like.
Pull them when the center has moist crumbs. You don’t want a clean toothpick for fudgy brownies. If they bake too long, they’ll dry out fast once they cool.
Try a 9×9 pan for thicker brownies. You’ll need a longer bake time (usually 28 to 35 minutes), but the extra thickness is great if you like a deeper fudge bite.
Swap melted butter for a richer taste. Vegetable oil gives great chew, but melted butter adds a little more flavor. I do it when I want them to taste more “from scratch.”
Add espresso powder if you like darker chocolate. A small amount won’t make them taste like coffee, it just bumps up the chocolate flavor.
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 brownies. I like it best when the brownies are at room temperature or slightly warm.
- Ice cream: Serve a square with vanilla ice cream. If you used chocolate chips, this combo is especially good.
- Whipped cream: A simple dollop of whipped cream is nice if you’re serving these on a dessert plate. Add a few extra sprinkles on top if it’s for a party.
- Fruit: Strawberries or raspberries are good on the side if you want something fresh with them. 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 brownies covered at room temperature for 2 to 3 days. I keep them in the pan with foil over the top, or move squares to a container once they’re fully cool.
For a slightly firmer, fudgier texture, you can store leftovers covered in the fridge for up to 4 days. I usually let a square sit out for a few minutes before eating, or warm it briefly.
You can also freeze individual portions if you want them to last longer. Wrap squares well, freeze, then thaw in the fridge overnight or at room temperature.
If you’re making these ahead for an event, bake the day before and slice once they’re completely cool. The sprinkles on top stay brightest when they aren’t handled too much.
A few quick answers
This section covers a few extra details that may help before you head to the recipe card.
Recipe FAQs
What kind of sprinkles work best in brownies?
I like rainbow jimmies best. They hold their shape and color better than nonpareils, and they don’t bleed as much into the batter.
How do I know when these brownies are done?
Look for set edges and a center that’s no longer wet-looking. A toothpick in the middle should come out with moist crumbs (not raw batter, but not totally clean either).
Can I bake these in a 9×9 pan instead?
Yes, you’ll get thicker brownies. Plan on baking about 28 to 35 minutes, and start checking early since ovens and mixes vary a bit.
Can I swap the vegetable oil for butter?
You can use melted butter in place of the oil for a richer flavor. The texture may be a little less “chewy” than the oil version, but still very fudgy if you don’t overbake.
Do chocolate chips make the brownies too sweet?
Not if you use semi-sweet chips. If you’re sensitive to sweetness, I’d skip the chips and just stick with the sprinkles.
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 Brownies
INGREDIENTS
Brownie Batter
- 1 box fudge brownie mix 18 to 19 oz
- 2 large eggs
- 1/2 cup vegetable oil
- 1/4 cup water
- 1 tsp vanilla extract
- 1/2 cup rainbow sprinkles
- 1/2 cup semi sweet chocolate chips optional.
Pan And Topping
- nonstick cooking spray or softened butter
- parchment paper optional
- 2 tbsp rainbow sprinkles.
INSTRUCTIONS
Prep
- preheat oven to 350 F
- grease a 9x13 inch baking pan and line with parchment if using
- whisk eggs vegetable oil water and vanilla in a large bowl then add brownie mix and stir just until combined.
Bake And Cool
- fold in 1/2 cup sprinkles and chocolate chips if using then spread batter evenly in pan and sprinkle 2 tbsp sprinkles over the top
- bake until edges are set and a toothpick inserted in the center comes out with moist crumbs 23 to 28 minutes
- cool in pan at least 30 minutes before slicing for clean squares.
