- 1 cup milk
- 1/4 cup flour
- 1 cup vegetable shortening (such as Crisco®)
- 1 cup white sugar
- 1 teaspoon vanilla extract
- Cook the milk and flour in the top of a double boiler over just-barely simmering water, stirring frequently and scraping down the sides with a rubber spatula until thickened, about 5 minutes. Place the mixture in the refrigerator until chilled.
- Combine the vegetable shortening, sugar, and vanilla extract with an electric mixer until well blended. Beat the chilled milk mixture into the shortening mixture until fluffy.