These Ganache-Stuffed Cosmic Brownie Cookies are everything I love about a nostalgic treat with a decadent twist. Each cookie features a chewy, chocolatey brownie exterior and a rich, creamy ganache surprise inside, finished with a cheerful sprinkle topping that brings out the kid in me.

Why You’ll Love This Recipe

I love how these cookies balance texture and flavor—crispy edges, fudgy centers, and that luscious pocket of ganache in the middle. They remind me of the classic cosmic brownies I used to eat, but in a more grown-up, indulgent cookie form. Whether I want to impress guests or just enjoy a cozy moment at home, these cookies never disappoint.

Ingredients

(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)

For the Ganache:

3.5 oz good quality chocolate (I use a mix of 35% milk and 57% semisweet), finely chopped
¼ cup heavy cream

For the Cookies:

2 cups all-purpose flour
6 tablespoons Dutch-process cocoa powder
1 teaspoon baking soda
½ teaspoon kosher salt
4 oz semisweet chocolate (50-60%)
¾ cup unsalted butter, at room temperature
1 cup packed brown sugar
½ cup granulated sugar
2 large eggs, at room temperature
2 teaspoons vanilla extract
Rainbow bit chips or other sprinkles

Directions

To make the ganache, I start by placing chopped chocolate in a bowl. I heat the cream just until it simmers, then pour it over the chocolate. After sitting for 30 seconds, I whisk it slowly until smooth. I let the ganache cool and thicken to a peanut butter-like consistency.
I pipe or spoon small mounds of ganache onto a parchment-lined tray—about ½ tablespoon each—and freeze them until solid, usually 30 minutes.
For the cookies, I whisk together flour, cocoa, baking soda, and salt. Then I melt the semisweet chocolate and let it cool.
In my mixer, I beat the butter and sugars until fluffy. I add eggs one at a time, then vanilla, followed by the melted chocolate. I slowly add the dry ingredients and mix until just combined.
I chill the dough for about 30 minutes until it’s firm enough to shape.
To assemble, I preheat my oven to 350°F and line baking sheets with parchment. I divide the dough into small balls, flatten two for each cookie, sandwich a frozen ganache disc between them, and seal the edges. I press the tops into sprinkles and place them on the baking sheet.
I bake for 9–11 minutes until set and puffed. While still warm, I swirl a cookie cutter around each to make them perfectly round. After 10 minutes, I transfer them to a rack to cool.

Servings and Timing

Servings: 24 cookies
Prep time: 30 minutes
Chill time: 30–60 minutes
Cook time: 10 minutes
Total time: Around 2 hours

Variations

I like swapping milk chocolate for all semisweet or even dark chocolate when I want a deeper cocoa flavor.
For a holiday twist, I use themed sprinkles.
If I don’t feel like stuffing, I skip the ganache and just make brownie cookies—they’re still amazing.

Storage/Reheating

I store the cookies in an airtight container at room temperature for up to 5 days.
For longer storage, I freeze the unbaked, stuffed dough balls. I bake them straight from frozen, adding a couple of extra minutes to the bake time.
Reheating baked cookies for 10–15 seconds in the microwave gives the ganache that freshly melted feel.

FAQs

How do I keep the ganache from leaking?

I make sure the ganache is completely frozen and fully enclosed in dough before baking. I press the edges well to seal.

Can I make these ahead?

Absolutely. I make the ganache and cookie dough a day in advance and assemble the cookies right before baking.

Do I need Dutch-process cocoa?

I prefer Dutch-process for the rich, smooth flavor, but if I only have natural cocoa, I still use it—just expect a slightly different taste and texture.

Can I skip the sprinkles?

Sure. Sometimes I go sprinkle-free if I want a more grown-up look or swap them for mini chocolate chips.

How do I make them perfectly round?

As soon as they come out of the oven, I gently swirl a round cutter around each cookie to shape them neatly.

Conclusion

These Ganache-Stuffed Cosmic Brownie Cookies are the kind of treat I keep coming back to. They’re rich, chewy, fun to make, and even more fun to eat. Whether I bake them for a party or just a quiet afternoon indulgence, they always hit the spot.