ding dong filling

1 cup milk

5 Tbs flour

1 1/2 cup powdered sugar

1/2 cup shortening--room temperature

3/4 cup unsalted butter--room temperature

1/2 tsp vanilla

1/4 tsp salt

Over low heat, cook milk and flour in a saucepan until it makes a thick paste. Use a whisk to break up lumps. Let cool.  In mixer using whisk attachment, beat shortening, butter, sugar, salt and vanilla. Add in cooled flour paste and whip until light and fluffy.  Add more sugar if you want a sweeter taste.