Whisk milk and flour together in a pot over medium heat

Keep stirring until it has reached a thick consistency, add vanilla and stir in. Set aside to cool

In a separate bowl, using a handmixer, mix butter and sugar until fluffy. Make sure butter is at room temperature or this recipe will not work, do not warm in microwave

Slowly add in the cooled flour mixture to the butter and sugar mixture and mix until it resembles whipped cream.