Cosmic Brownie Cookies
These rich and chewy cosmic brownie cookies are packed with deep chocolate flavor and a fun burst of rainbow candy chips in every bite. Made with an easy no-chill cookie dough, each cookie is finished with a smooth chocolate ganache that gives them the classic cosmic brownie feel. They’re the perfect quick dessert when you’re craving something extra fudgy and loaded with chocolate.
Ingredients
Cookie Dough
- 1 ¾ cup All-purpose flour Spooned and leveled
- ¾ cup Dutch-process cocoa powder Do not substitute regular cocoa
- 1 tsp Baking soda
- ½ Baking powder
- ½ tsp Salt
- 1 tsp Espresso powder Optional but strongly recommended
- 1 cup Salted butter Room temperature (65–67°F)
- 1 cup Brown sugar Packed
- ½ cup Granulated sugar
- 2 tsp Pure vanilla extract
Chocolate Ganache
- 4 oz Dark chocolate Finely chopped
- ¼ cup Heavy cream
Topping
- ½ cup Mini rainbow-coated chocolate chips Mini M&Ms work as a substitute
Instructions
- Group: Make the Cookie Dough1. Preheat your oven to 350°F (175°C). Line two baking sheets with parchment paper and set aside.2. In a medium bowl, whisk together the flour, dutch-process cocoa powder, baking soda, baking powder, salt, and espresso powder until evenly combined. Set aside.3. In the bowl of a stand mixer fitted with the paddle attachment (or using a hand mixer), beat the room-temperature butter, brown sugar, and granulated sugar together on medium-high speed for 3–4 minutes, until the mixture is pale, light, and fluffy.4. Add the eggs and vanilla extract to the butter mixture. Beat on medium speed until fully incorporated and the mixture looks smooth and glossy, about 1 minute.5. Add one-third of the flour-cocoa mixture to the wet ingredients and mix on low speed. Repeat with the remaining two additions, mixing just until no flour streaks remain. Do not overmix.Group: Scoop and Bake6. Use a medium cookie scoop to portion the dough into balls (about 1.5 tablespoons each). Place them on the prepared baking sheets at least 2 inches apart.7. Bake one sheet at a time in the center of the oven for 7–10 minutes, until the edges are set and the tops look slightly puffed. 8 minutes is the sweet spot for a fudgy center. Do not overbake.8. Immediately after removing from the oven, use a round biscuit cutter to gently swirl each cookie into a neat circle. This step is optional but gives a clean, bakery-style look. Let cookies cool on the pan for 5 minutes, then transfer to a wire rack to cool completely.Group: Make the Ganache9. Place the finely chopped dark chocolate in a small heatproof bowl.10. Heat the heavy cream in the microwave in 20-second increments until hot and steaming but not boiling — about 40 seconds total. Pour the hot cream over the chopped chocolate. Let it sit undisturbed for 2–3 minutes.11. Stir slowly from the center outward until the ganache is completely smooth and glossy. If any chocolate remains unmelted, microwave the bowl for 5–10 seconds and stir again.Group: Top and Set12. Spoon approximately 1 teaspoon of ganache onto each fully cooled cookie. Use the back of the spoon to gently spread it toward the edges.13. Immediately scatter mini rainbow-coated chocolate chips over the ganache before it sets.14. Allow the cookies to rest at room temperature for about 1 hour until the ganache is fully set before serving or storing.
Notes
- Butter temperature matters. Room temperature butter should feel cool to the touch and hold its shape — not soft, greasy, or shiny. Aim for 65–67°F. Leave it out for about an hour before baking.
- Don't overbake. The cookies will look slightly underdone in the center when you pull them out — that's intentional. They continue to set as they cool and give you the perfect fudgy texture.
- Cool completely before ganaching. Even slightly warm cookies will cause the ganache to melt and slide off. Give them a full rest on the wire rack first.
- Storage: Once the ganache has fully set, store cookies in an airtight container at room temperature for up to 3–4 days, with parchment paper between layers.
- Freezing: Freeze fully set cookies in a freezer-safe container with parchment between layers for up to 3 months. Thaw at room temperature for 30 minutes before serving.
- Freeze the dough: Scoop dough balls and freeze on a lined sheet until solid, then transfer to a freezer bag. Bake from frozen at 350°F, adding 2–3 minutes to the bake time.