The recipe I use is 2 sticks salted butter, 3/4 cup hi ratio shortening, 2 tsp pure vanilla extract, 1 cup cocoa powder, 2 lb bag of powdered sugar sifted minus 1 cup, about 6 tbs milk. I combine butter and shortening until smooth, add in cocoa powder until combined. Add in sugar slowly, it’ll be crumbly. Add in vanilla extract and milk. I never measure the milk any more, just add a bit at a time until I get the consistency I like. Hope this helps you.