I eye my buttercream recipe. I use 2 sticks butter, light cream, vanilla and about a bag of sugar. When I mix in kitchenaid and then coat my cake my frosting is not smooth. It's full of ripples and air pockets. It's fine usually because I fondant all my cakes but lately have been trying just frosted cakes. I've tried milk instead of cream so it wouldn't be so whippy but then it looks wet and separates-I notice. How do I get a smooth buttercream? (choc or vanilla)

My recipe is as follows,

2lbs of confectioners sugar 

4-5 tbsp of heavy whipping cream

1 cup of butter (2 sticks)

1 cup vegetable shortening

1tbs meringue powder

1tbs clear vanilla extract

1/2 tsp almond extract. 

Cut butter sticks into cubes. Place on the mixer's bowl. Add shortening, vanilla and almond extracts. Beat with the paddle attachment. (Make sure butter is room temp tho). After creaming that, scrape the bowls sides with a spatula. 

Add meringue powder to the sugar and mix well. On a med speed, add sugar little by little. When the mixer starts to work had, add the heavy whipping cream. Alternating it with the sugar. For creamier frosting, add more cream. For thicker frosting, add more sugar. 

After all is combined, scrape the sides of the bowl again and beat on a med to high speed for two mins. 

For high humidity, I used this recipe and changed from milk or whipping cream to water.  Didn't change the texture or taste, but it did hold up longer.  Love this recipe!

Also try letting your mixer run for a good 10 minutes on low - best if the buttercream comes up to the top of the paddle.  I make two batches and the combine them in my 5qt.  This fills the bowl and then I put it on low and let it go for at least 10 min.  This will eliminate a lot of the bubbles and makes my buttercream creamy, smooth.  Or you could run a spatula through your batch, smashing along the side of the bowl to get the air out.