01 - Preheat the oven to 400°F. Line a baking sheet with parchment paper.
02 - Toss pitted and halved cherries with 1 tablespoon sugar and 1 teaspoon vanilla extract. Spread on the prepared baking sheet and roast for 12-15 minutes until juicy and slightly caramelized. Allow to cool completely.
03 - Reduce oven temperature to 350°F. Grease an 8-inch square baking pan with butter and line with parchment paper, leaving an overhang for easy removal.
04 - Set a heatproof bowl over a saucepan of simmering water. Add butter and chopped chocolate, stirring constantly until completely melted and smooth. Remove from heat and let cool slightly.
05 - Whisk granulated sugar and brown sugar into the melted chocolate mixture until well incorporated. Add eggs one at a time, whisking thoroughly after each addition. Stir in vanilla extract and salt.
06 - Sift flour and cocoa powder directly into the bowl. Gently fold with a spatula until just combined, being careful not to overmix.
07 - Gently fold most of the roasted cherries into the batter, reserving a few pieces for the topping.
08 - Pour batter into the prepared pan and smooth the top evenly. Scatter reserved roasted cherries over the surface. Bake for 25-28 minutes until a toothpick inserted in the center comes out with moist crumbs. Avoid overbaking.
09 - Allow brownies to cool completely in the pan before lifting out using the parchment overhang. Cut into 12 equal squares.