This is not your 'whip together in 5 minutes' frosting, but I think it is well worth the extra effort.
Chocolate FrostingRecipe from Our Best Bites
2/3 c. granulated sugar
1/3 c. flour
3 Tbsp. cocoa powder
1 c. milk
1 c. butter
1 c. semi-sweet chocolate chips
Melt your chocolate chips in microwave safe bowl, stirring every 30 seconds until smooth.
Set it aside to cool slightly.
In a small saucepan, whisk together sugar, flour, cocoa, and milk; bring to a boil, whisking frequently.
Boil 1-3 minutes or until thickened like a thinned pudding.
Remove pan from heat and strain mixture into a small bowl to remove any lumps.
Cool completely in the refrigerator or freezer.
When chocolate flour mixture is cooled, beat the butter until creamy, about 1 minute.
Beat in the cooled chocolate mixture until well combined and fluffy, about 1 minute.
Finally add in melted chocolate and beat again until well combined and fluffy, about 2 minutes.
If desired, add additional cocoa powder to taste, up to 4 tablespoons more.
Spread or pipe frosting on to cupcakes or cake.