This frosting is creamy, soft and not too sweet. It will be soft while you decorate with it but it will crisp up slightly as it dries, which makes it the perfect frosting for decorating cookies!
Mix together the shortening and vanilla with an electric mixer. Beat until creamy (at least 1 minute).
Add the powdered sugar one cup at a time.
As the mixture starts to become dry, begin adding the milk a little bit at a time alternating with the powdered sugar.
Beat until smooth and creamy. Use more or less milk to reach desired consistency.
Add food coloring, if desired. (It makes decorating more fun!)
I know many people are against using shortening, and I was too, but the shortening is what makes this frosting firm up, so it's really the best. I use Spectrum Organic Shortening, which is healthier than the regular brands. You can swap half the shortening for butter but the frosting will have a softer finish and will not stack well.