Preheat the oven to 400°F.
Toss the pitted cherries with olive oil and spread them on a baking sheet.
Roast for 15 minutes until they are soft and slightly caramelized. Remove from the oven and let cool.
In a large mixing bowl, combine sugar, cocoa powder, flour, salt, and baking powder. Whisk until well blended.
In a separate bowl, mix the melted butter, eggs, and vanilla extract until smooth.
Gradually add the wet ingredients to the dry ingredients, stirring until just combined.
Gently fold in the roasted cherries.
Pour the brownie batter into a greased 8x8-inch baking pan.
Bake in the preheated oven for 20-25 minutes or until a toothpick inserted in the center comes out with a few moist crumbs.
Allow to cool in the pan before slicing into squares.