I use the Wilton buttercream icing recipe that they teacher in their classes. However, I havent figured out how to make it a Chocolate buttercream. What chocolate to use etc . .
If you have a recipe that is easier then Wiltons that you like better please share.

The Wilton Chocolate Buttercream Recipe is :

1 stick Butter
1/2 cup Vegetable Shortening
3/4 cup Cocoa or 3 oz of melted unsweetened chocolate
4 cups confectioner's sugar
3-4 tablespoons of milk

I have made this recipe a few times and didn't like the flavor when I used all the sugar and the powdered cocoa, it was to sweet, and gritty.

What I do when I make it is use the melted chocolate which gets rid of the grittiness the cocoa was creating. I try to use a good chocolate, like Gihardelli for a good flavor .
Also I add a splash of vanilla extract and only use 2 and half cups of sugar, 4 just really isn't necessary to me...

Good luck !

I add 1/4 tsp. almond flavoring as well as vanilla. Gives it just a little different flavor. VERY tasty.

There are so many chocolate buttercream recipes. Don't just limit your recipe to Wilton. Go on the most saved recipes here as a start. The favorite buttercream recipes here are going to be easier to work with than the class recipe. When I took the class, I made a different buttercream and a different fondant for every class. You will soon find your favorites with better taste and better final results.