Recipe(tried): Chocolate Buttercream Frosting - Emma, Here you go!

Emma, this is what I use when I make my own. You will need to adjust the water amounts depending on what brand of shortening you use. I have used a wide variety and the water needed is always different. Start at the bottom end and work up from there a tablespoon at a time. It needs to be somewhat stiff, but still easily spreadable. The flavorings needed can usually be bought at any wal-mart in the craft section. Look wherever Wilton decorating products are sold. The clear should be used if you want white icing, and the flavor is better if you use the wilton versus the darker McCormick. Add the lower amount of cocoa powder then add more if needed. This frosting will be much lighter in color than you are used to. The dark color can be achieved by adding brown paste or powder food coloring. There are many other buttercream icing recipes posted here, but I know that this one will crust over when made correctly. Good luck, I would love to know how it turns out!

CHOCOLATE BUTTERCREAM FROSTING

2 cups Crisco vegetable shortening
2 pounds powdered sugar, sifted 3 times
6 to 8 Tbsp cocoa powder
2 tbsp clear vanilla flavoring
1 tbsp clear butter flavoring
3 to 6 tbsp water

Cream shortening. Add sifted sugar slowly. Add flavorings and water as needed for stiff, but spreadable consistency.