Homemade Nutter Butter Cookies

Beat 1/4 cup butter until smooth and creamy.

Mix in 1/2 cup peanut butter, then 1 cup powdered sugar, milk and 1/4 tsp vanilla until combined.

Gradually mix in remaining 1/2 cup powdered sugar until smooth and spreadable.

Spread 1 tbsp filling on the flat side of one cookie, top with another cookie to make sandwiches.