Yield: 16-ish brownies, depending on how you cut ‘em
- ½ cup + 2 Tbsp (142g) unsalted butter
- ¾ cup (149g) granulated sugar
- 1/3 cup (71g) light brown sugar, packed
- 1 cup (88g) unsweetened cocoa powder, sifted
- 2 large eggs, room temp
- 1 large egg yolk, room temp
- 1 Tbsp (20g) light corn syrup
- 1 tsp vanilla extract
- 2/3 cup (85g) all-purpose flour
- 1 Tbsp (7g) cornstarch
- ¼ tsp salt
- ½ cup (114g) heavy cream
- 1 ½ cups (255g) semi-sweet chocolate chips
- Heat oven to 350°F. Grease and line an 8" x 8" metal baking pan with parchment paper; set aside.
- In a large, microwave-safe bowl, melt butter. Whisk in sugars and cocoa powder.
- Allow to cool slightly, then add eggs, egg yolk, corn syrup, and vanilla, whisking until fully combined and glossy.
- Sift in flour, cornstarch, and salt. Mix just until combined.
- Pour thick batter into prepared pan, smoothing the top with offset spatula or the back of a spoon.
- Bake for 25 minutes.
- Transfer pan to wire rack. Allow to cool completely.
- Once your brownies are totally cool, make the chocolate frosting. In a microwave-safe bowl, heat cream for 1 minute.
- Add chocolate chips and allow to sit for 3 minutes. Stir until smooth.
- Pour frosting over cool brownies, tilting pan this way and that way to evenly spread the frosting. Finesse with an offset spatula or back of a spoon, if necessary.
- Sprinkle rainbow sunny seeds on top. Use just a few to keep in line with the original cosmic brownies or add more (like we did!) because you’re the boss in your own kitchen.
- Refrigerate brownies for 1–2 hours to allow frosting to set.
- Once your frosting is set, remove brownies from pan by pulling up on the parchment paper, then cut your brownies.
NOTE: We recommend using a chef’s knife and running it under hot water before each cut. A clean, hot knife will give you the neatest cuts.