1/3 cup butter, softened
1–1/2 cups confectioners sugar
1 egg, separated
2 teaspoons Rain’s Choice pure Vanilla Extract
1/2 cup heavy cream
1/8 teaspoon ground nutmeg
In a small mixing bowl, cream butter with sugar, egg yolk, and vanilla extract; blend well. Beat cream until stiff; fold into butter mixture (sauce will be foamy). Sprinkle with nutmeg.
Find it online: https://vanillaqueen.com/vanilla-chiffon-sauce/