Preheat oven to 350°F. Grease and line a 9″x9″ glass pan with parchment paper. Set aside.
In a microwave-safe bowl, melt the butter. Remove from microwave, stir in sugar, and melt again for 30 seconds. You want the sugars and butter to bubble up slightly, but not burn. This amount of time should do the trick.
Remove mixture from microwave and stir in coffee. Allow to cool slightly before whisking the cocoa powder, eggs, and vanilla extract. Last, mix in flour and salt.
Pour batter into prepared pan. Bake for 30 minutes, or until a knife inserted in the center of the brownies comes out mostly clean (a little batter is fine, it will turn into delicious fudgyness). Allow to cool for 15 minutes before removing from pan. Allow to cool completely.
To make the frosting, whip together all ingredients until light and fluffy. Frost brownies and sprinkle with crumbled oreos, then cut into 9 large squares.