Okay, this is HANDS DOWN my favorite frosting recipe so far. It is yummy and fairly easy to do.
1 cup softened butter [cream it in mixer]
3 1/2 cups powdered sugar [add it slowly to the creamed butter]
1/2 cup cocoa powder [again add it slowly... if you don't you will have clouds of chocolate ALL over your kitchen!]
2 tsp vanilla
4 Tbsp heavy cream
[one caveat: because of the butter and cream in this, you MUST refrigerate frosted cupcakes and any leftover frosting]