Fudge Frosting

From Cupcake Bakeshop:

To make it sweeter increase the semisweet by a couple of ounces and decrease the bittersweet or unsweetened. The bittersweet gives it a bite, the unsweetened a rich cocoa flavor, and the semisweet a sweetness... So, add and subtract based on what you are trying to get at flavor wise.

4 oz bittersweet chocolate
2 oz unsweetened chocolate
10 oz semisweet chocolate
2 sticks butter
5 cups powdered sugar
pinch salt
2 tsp vanilla
1 cup whole milk

1. Melt chocolates and butter over double boiler.
2. Stir until smooth.
3. Set aside to cool slightly.
4. Sift powdered sugar and salt into a bowl.
5. Combine milk and vanilla.
6. Add milk/vanilla mixture to sugar/salt mixture.
7. Whisk until incorporated.
8. Add melted chocolate/butter mixture to milk/vanilla/sugar/salt mixture.
9. Stir until smooth.
10. chill it in the fridge for 20 minutes, until thick enough to frost.