Preheat the oven to 350°. Line an 8 x 8 inch baking pan with parchment paper.
In a small saucepan, melt ½ cup of butter over low heat. Once the butter is melted, remove the pan from heat. Add the broken pieces of bittersweet chocolate and allow them to melt.
While the butter and chocolate are melting, combine the sugars in a large bowl. In a separate bowl, combine the flour, cocoa powder, baking powder and salt.
Add the melted butter and chocolate to the sugars and mix thoroughly. Add the eggs and vanilla to the chocolate mixture. Mix until well combined.
Add the flour mixture to the chocolate mixture and mix until well combined. Fold in the chocolate chips.
Spread the batter into the parchment lined baking pan.
Drop dollops of cherry jam onto batter and swirl into batter.
Bake for 25-30 minutes. Begin testing the brownies to see if they are baked at 25 minutes. A toothpick inserted into the brownies should have a few sticky brownie crumbs stuck to it letting you know that they are done.
Remove brownies from the oven and cool completely. Once the brownies are cool, lift the parchment paper and brownies from the pan and transfer to a cutting board.
For the Cherry Buttercream
Combine the butter, powdered sugar, cherry jam, cherry flavoring, vanilla and milk in the bowl of your stand mixer.
Mix until light and fluffy.
Spread over the cooled brownies
Cut the brownies into 16 squares.
Brownies can be stored at room temperature for up to a week but they won't last that long.