Slowly mix in 3 1/2 cups of powdered sugar and 1/3 cup of heavy cream on a low speed. Scrape the sides and bottom of the bowl as needed with a rubber spatula. Mix on low until the ingredients are fully incorporated and the
desired consistency is reached. If the frosting seems too thick, add an extra Tbsp of heavy cream. If it's too thin, add another 1/4 cup of powdered sugar.