Cosmic Brownie Mix Cookies

A nostalgic copycat turned cookie: fudgy brownie dough scooped into cookies, topped with chocolate fudge frosting and rainbow crunch sprinkles—ready in under an hour.

Why You'll Love This Recipe
- Five simple pantry-friendly ingredients make these a fast, accessible option for busy days—ready from start to finish in about 52 minutes with only 10 minutes active prep time.
- The texture is fudgy in the center with slightly set edges, offering that classic brownie mouthfeel but in cookie form for easier serving and sharing.
- Make-ahead friendly: the dough chills well, and un-decorated cookies freeze for up to three months—ideal for planning holiday trays or bulk baking.
- Customizable: use your preferred boxed mix and frosting variations to dial in flavor intensity; the recipe also accepts small swaps like oil for butter.
- Kid-friendly and festive: rainbow crunch sprinkles add nostalgia and color, making these perfect for parties, school treats, or casual celebrations.
- Minimal equipment required—no stand mixer necessary; a bowl, spoon, cookie scoop, and baking sheet are enough for success.
In my kitchen these cookies became a go-to because they are forgiving and fast. The first time I took them to a potluck the plate emptied so quickly that neighbors were asking for the recipe. My kids like squeezing the frosting on and sprinkling the rainbow crunch themselves, which turns decorating into a family activity.
Ingredients
- 18-ounce box of brownie mix: Choose a high-quality brand that lists cocoa and real chocolate as primary ingredients; I prefer the Ghirardelli/ Pilsbury-style mixes for dense results. Avoid mixes known to spread excessively, and if using a thinner mix, add 1/4 cup of flour.
- 2 large eggs: Bring eggs to room temperature for better incorporation and a slightly more tender crumb. Room-temp eggs help the batter come together smoothly and contribute to the fudgy center.
- 1/4 cup melted butter (or vegetable oil): Melted butter adds richness and flavor; substitute vegetable oil in a 1:1 ratio if needed for a dairy-free option, though texture will be slightly different.
- 1 cup chocolate fudge frosting: Use a spreadable tub frosting labeled chocolate fudge for a glossy, thick finish; warm slightly before spreading so it thins but does not become runny.
- 5.25-ounce container rainbow crunch sprinkles: The candy-coated crunch is essential for texture contrast—find these in the baking aisle with sprinkles or purchase a similar multicolor crunchy sprinkle mix.
Instructions
Preheat and prepare: Set the oven to 350 degrees Fahrenheit and line a rimmed cookie sheet with parchment paper. A lined sheet prevents burning and helps cookies slide off easily after baking. Position the rack in the center of the oven for even heat. Mix the batter: In a large mixing bowl, stir together the brownie mix, 2 large eggs, and 1/4 cup melted butter until the mixture is uniform and slightly glossy. Avoid overmixing; stop when no dry pockets remain. The batter will be much thicker than typical cookie dough, closer to a scoopable brownie dough. Scoop and chill: Using a heaping tablespoon or a medium cookie scoop, portion the dough onto the prepared sheet about two inches apart to allow for slight spread. Transfer the tray to the refrigerator for thirty minutes. Chilling firms the fat and reduces spread, yielding tall, fudgy cookies instead of thin discs. Bake: Bake for 11 to 12 minutes, until the edges are set but the centers still look soft—this is the cue for fudgy texture. Rotate the pan halfway if your oven has hot spots. Remove and allow cookies to cool on the sheet for five minutes to finish setting before transferring to a wire rack. Warm frosting and decorate: Microwave the chocolate fudge frosting for about 20 seconds in a microwave-safe bowl, stirring halfway through. You want it loosened but not soupy. Spread roughly one tablespoon of frosting on each cooled cookie, then immediately top with a generous sprinkle of rainbow crunch.
You Must Know
- These are best when removed from the oven while centers still look slightly underbaked; they continue to set during the five-minute rest on the baking sheet.
- Dough freezes well: freeze scooped dough balls on a tray, then bag for up to three months. Thaw in the refrigerator before baking to preserve texture.
- Use a sturdy frosting labeled chocolate fudge for the best glossy finish; thin it only enough to spread easily without sliding off the cookie.
- Choose a thicker brownie mix for dense cookies. If your chosen brand tends to spread, stir in 1/4 cup of all-purpose flour to stabilize the batter.
- Store finished cookies in an airtight container at room temperature for up to three days; separate layers with parchment to protect the frosting and sprinkles.
My favorite part of making these is how quickly they bring people together. Once I set out a plate, kids and adults alike gravitate to the colors and chocolate. Baking them has become my go-to when I need a reliable treat that feels homemade but requires minimal effort and fuss.
Storage Tips
To maintain texture and frosting appearance, store these cooled cookies in a single layer or in stacked layers separated by parchment paper inside an airtight container at room temperature for up to three days. Refrigeration can dry them out, so only refrigerate if your kitchen is very warm; allow refrigerated cookies to come to room temperature before serving. For longer storage, freeze unfrosted baked cookies in an airtight, freezer-safe container for up to three months. Thaw at room temperature; add fresh frosting and sprinkles after thawing for best presentation.
Ingredient Substitutions
If you need a dairy-free option, substitute the melted butter with a neutral vegetable oil in equal measure and use a dairy-free chocolate frosting. For a slightly cakier texture, add one extra egg white; for extra chew, fold in 2 tablespoons of chocolate chips. If your chosen brownie mix tends to spread, stir in 1/4 cup all-purpose flour to tighten the structure. You can swap rainbow crunch for chopped candy pieces or nonpareils, but note that texture and moisture balancing will change slightly.
Serving Suggestions
Serve these on a colorful platter at parties or as part of a dessert board with brownies, blondies, and cookies for variety. They pair nicely with cold milk, hot chocolate, or a simple espresso. Garnish with a few extra sprinkles just before serving for maximum visual appeal. For gift-giving, stack in a small box with parchment between layers and include a chilled gel pack if shipping in warm weather.
Cultural Background
These cookies are a playful American adaptation of the candy-coated brownie that became popular as a bakery staple in the late 20th century. The idea of topping chocolate desserts with colorful candies taps into Americana party and school-bake traditions, where bright colors and easy-to-eat formats are preferred. Adapting a boxed mix into a different form—cookies instead of a pan-baked brownie—is part of a long tradition of home cooks reimagining convenience products into homemade-feeling treats.
Seasonal Adaptations
Switch sprinkles to seasonal colors—red and green for winter holidays, pastels for spring, or orange and black for Halloween—to make these suitable for themed events. Substitute the chocolate frosting with salted caramel or peanut butter frosting for a fall twist. In summer, serve slightly chilled with a scoop of vanilla ice cream for an indulgent dessert sandwich.
Meal Prep Tips
Prepare dough and scoop onto a tray, cover tightly, and refrigerate for up to 48 hours before baking for fresher cookies on demand. Freeze scooped dough balls for up to three months; bake from thawed or partially thawed according to the bake time above. Bake a double batch and freeze undecorated cookies; thaw and frost as needed for easy entertaining.
Success Stories
I once brought a batch of these to a neighbor’s block party and a woman told me they tasted exactly like the boxed bakery brownies she bought as a child—only easier to share. My kids love helping frost them and take pride in making each cookie look just a little different. Over the years I’ve mailed them in care packages as a small, colorful treat and always include a sheet of parchment to keep the layers separated.
These cookies are proof that with a few pantry staples and one uninterrupted half hour, you can make a nostalgic, crowd-pleasing dessert that keeps well and travels even better. Make them your own by trying different frostings, sprinkles, or mix brands until you find the combination that feels just right.
Pro Tips
Chill the scooped dough for at least 30 minutes to prevent excessive spread and keep the cookies thick and fudgy.
Remove the cookies from the oven while centers still look slightly soft; they will finish setting on the pan and remain fudgy.
Warm the frosting briefly until spreadable but not runny to keep the topping glossy and avoid melting the sprinkles.
Use parchment paper on the baking sheet to prevent sticking and burning on the bottoms.
This nourishing cosmic brownie mix cookies recipe is sure to be a staple in your kitchen. Enjoy every moist, high protein slice — it is perfect for breakfast or as a wholesome snack any time.
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Cosmic Brownie Mix Cookies
This Cosmic Brownie Mix Cookies recipe makes perfectly juicy, tender, and flavorful steak every time! Serve with potatoes and a side salad for an unforgettable dinner in under 30 minutes.

Ingredients
Main
Instructions
Preheat and prepare
Preheat oven to 350 degrees Fahrenheit and line a rimmed cookie sheet with parchment paper. Position the oven rack in the center for even baking.
Mix batter
In a large mixing bowl, stir together the brownie mix, 2 large eggs, and 1/4 cup melted butter until combined and glossy. Do not overmix; stop when no dry streaks remain.
Scoop and chill
Scoop heaping tablespoons of batter onto the prepared sheet about two inches apart. Chill the tray in the refrigerator for 30 minutes to firm the dough and reduce spread.
Bake
Bake for 11 to 12 minutes until edges are set but centers are still slightly soft. Allow cookies to cool on the sheet for 5 minutes, then transfer to a wire rack to cool completely.
Warm frosting and decorate
Microwave the frosting for about 20 seconds, stirring halfway, until it is spreadable but not runny. Spread about one tablespoon on each cookie and immediately top with rainbow crunch sprinkles.
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Comments (1)
This recipe looks amazing! Can't wait to try it.
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