Prepare brownie batter by melting dark chocolate and butter together
Mix flour, sugar, brown sugar, vanilla essence, coffee powder, cocoa powder, salt, and baking powder
Beat eggs and combine with chocolate mixture
Fold in dry ingredients to create brownie batter
Bake brownie until cooked through
Prepare rum ganache by heating cream and melting dark chocolate with unsalted butter
Add dark rum and salt to ganache mixture
Pour rum ganache over cooled brownie
