Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper and spread the halved fresh cherries in a single layer. Sprinkle with sugar and roast them for about 10 minutes until they are soft and the sugar has caramelized slightly.

Lower the oven temperature to 325°F (160°C). Prepare an 8x8 inch baking pan with non-stick spray and parchment paper for easy removal.

In a medium bowl, sift together the all-purpose flour, Dutch process cocoa powder, cornstarch, and salt. Set aside.

In another bowl, beat together the granulated sugar, eggs, and extra egg yolk on medium speed for about 5 minutes until light and fluffy.

Slowly pour the melted butter, vegetable oil, and vanilla extract into the egg mixture, mixing gently to incorporate.

Fold the sifted dry ingredients into the wet mixture using a rubber spatula until just combined.

Carefully fold in half of the roasted cherries and chocolate chips into the brownie batter for even distribution.

Pour the brownie batter into the prepared pan and bake for 40-50 minutes. Check for doneness with a toothpick.

Allow the brownies to cool completely in the pan on a wire rack before lifting them out and cutting into squares.