Buttercream is probably the most basic frosting you can learn how to make. (Though I think cream cheese frosting is even easier!) Here is the recipe I always use.
By the way, like the cream cheese frosting recipe, this is an easily adaptable recipe. You can switch out the kind of extract you use, drop in some cocoa powder, or add something like cookie butter. And with a little food coloring, the possibilities are endless!
Okay, last thing. I recommend just going ahead and using cream instead of milk here. (You’re only putting in a little anyway!) The taste is so so worth it.
Basic Buttercream Frosting
Makes enough for 12 cupcakes or for half of a standard double-layer 9″ round cake.
3/4 cup unsalted butter, room temp
2 1/2–3 cups powdered sugar
2–4 TB milk or cream
1 tsp vanilla
a pinch of salt (optional)
Cream the butter for a good few minutes.
Gradually beat in some of the powdered sugar.
Incorporate the milk or cream and vanilla.
Finish by incorporating the rest of the powdered sugar. The more you add, the stiffer your frosting will be. (Just be sure to test along the way, since your frosting can quickly become too sweet!)
Apply frosting to completely cooled cupcakes or cake.
Note: You may have some frosting left over. Freeze it in a plastic baggy, and the next time you need to frost something you can just let it thaw, snip off the corner of the bag, and frost to your heart’s content.