Preheat the oven to 350°F. Line a square 9 X 9-inch baking dish with a parchment paper sling or spray with baking spray. Set aside.
In a large microwave-safe bowl, combine bittersweet chocolate and butter. Microwave on high in 20-30 second bursts, stirring well between bursts of heat until melted and smooth. Whisk in cocoa powder.
4 ounces bittersweet chocolate, 3/4 cup salted butter, 1/2 cup natural unsweetened cocoa powder
Add granulated sugar and brown sugar, whisking well to combine. Add eggs and vanilla, beating well either by hand with a whisk or with an electric mixer.
1 cup (200g) granulated sugar, 1/2 cup (100g) brown sugar, 3 large eggs, 2 teaspoons vanilla extract
Sprinkle flour and salt over brownie batter and gently stir it in with a wooden spoon or spatula. Stir in chocolate chips and cherries.
3/4 cup (106g) all-purpose flour, 1/2 teaspoon salt, 1 cup semisweet chocolate chips, 1 cup halved fresh cherries
Pour brownie batter into the prepared baking dish and spread into corners. Batter will be thick.
Bake for 30-35 minutes, until a toothpick inserted into the center of the brownies comes out mostly clean with only a few crumbs attached. Do not over-bake.
Cool completely before cutting. Store in an airtight container for up to 5 days at room temperature or in a refrigerator.