Party Brownies Recipe
Introduction
These Party Brownies are rich, fudgy, and topped with a glossy chocolate frosting sprinkled with colorful rainbow sprinkles. They’re perfect for celebrations or anytime you want a crowd-pleasing dessert that’s fun and festive.

Ingredients
- 1 box brownie mix (usually 16-18 ounces)
- 6 tablespoons butter
- 1/3 cup milk
- 1 1/4 cups granulated sugar
- 1 teaspoon vanilla extract
- 1/2 teaspoon coarse kosher salt
- 1 cup semi-sweet chocolate chips
- Rainbow sprinkles
Instructions
- Step 1: Prepare the brownies according to the box directions and bake them in a 9×13 inch or slightly smaller rectangular pan. Allow them to cool for about an hour before frosting.
- Step 2: To make the frosting, melt the butter in a small saucepan over medium heat. Add the milk, sugar, vanilla extract, and salt, and bring the mixture to a rolling boil. Let it boil steadily for 45 seconds, timing carefully to avoid overcooking.
- Step 3: Remove the pan from heat and stir in the chocolate chips until smooth. If lumps remain, whisk the mixture for about a minute to fully combine.
- Step 4: Quickly pour the warm frosting over the cooled brownies and spread evenly. Immediately sprinkle with rainbow sprinkles before the frosting begins to set.
- Step 5: Let the frosting rest for 15-30 minutes to firm up, which helps when cutting clean slices. Serve and enjoy your party-ready brownies!
Tips & Variations
- Use a slightly smaller pan for thicker brownies and frosting if you prefer a richer treat.
- Swap rainbow sprinkles for chopped nuts or crushed candy for a different texture and flavor.
- Make sure to pour the frosting while it’s still warm so it spreads smoothly.
Storage
Store the brownies in an airtight container at room temperature for up to 3 days or refrigerate for up to a week. Reheat briefly in the microwave to soften the frosting before serving, if desired.
How to Serve

Serve this delicious recipe with your favorite sides.
FAQs
Can I use homemade brownies instead of boxed mix?
Yes, you can use your favorite homemade brownie recipe. Just be sure to let the brownies cool completely before applying the frosting for best results.
How long should the frosting boil?
The frosting mixture should boil steadily for 45 seconds to achieve the right texture. Use a timer to avoid overcooking, which can affect the frosting’s consistency.
PrintParty Brownies Recipe
Delight in these colorful Party Brownies featuring a rich homemade chocolate frosting topped with vibrant rainbow sprinkles. This fun and festive treat combines the ease of a classic boxed brownie mix with a luscious boiled chocolate frosting that sets to perfection, making it ideal for celebrations and gatherings.
- Prep Time: 15 minutes
- Cook Time: 30 minutes
- Total Time: 1 hour 45 minutes
- Yield: 12–16 servings 1x
- Category: Dessert
- Method: Baking
- Cuisine: American
Ingredients
Brownies
- 1 box brownie mix (16–18 ounces)
- 6 tablespoons butter
- 1/3 cup milk
Frosting
- 1 1/4 cups granulated sugar
- 1 teaspoon vanilla extract
- 1/2 teaspoon coarse kosher salt
- 1 cup semi-sweet chocolate chips
- Rainbow sprinkles
Instructions
- Make the brownies: Prepare the brownie batter following the package directions carefully. Pour the batter into a 9×13 inch or slightly smaller rectangular baking pan, ensuring even distribution.
- Bake the brownies: Bake according to the brownie mix package instructions, typically at 350°F for 25-35 minutes. Allow the baked brownies to cool for about an hour to ensure they are set before frosting.
- Make the frosting: In a small saucepan over medium heat, melt the 6 tablespoons of butter. Add milk, granulated sugar, vanilla extract, and coarse kosher salt. Bring this mixture to a consistent rolling boil and maintain the boil for 45 seconds exactly, using a timer to prevent overcooking.
- Mix in the chocolate: Remove the saucepan from heat and immediately add the semi-sweet chocolate chips. Stir continuously until the chocolate is fully melted and the frosting is smooth. Whisk vigorously if lumps remain.
- Frost the brownies: Quickly pour the warm frosting over the cooled brownies. Spread evenly with a spatula since the frosting sets rapidly. Immediately sprinkle rainbow sprinkles on top to decorate before the frosting hardens.
- Rest and serve: Let the frosted brownies rest at room temperature for 15 to 30 minutes to allow the frosting to set completely. Use a sharp knife to cut clean slices, then serve and enjoy the festive treat!
Notes
- Use a 9×13 inch pan or slightly smaller rectangular pan to achieve the right thickness for frosting.
- Work quickly when spreading frosting because it starts to set immediately once poured.
- For cleaner slices, allow the frosting to rest longer before cutting.
Keywords: party brownies, chocolate brownies, homemade frosting, festive dessert, rainbow sprinkles

