Gently melt the butter in a small saucepan on low-medium heat. Stir constantly, the butter will start to bubble. Keep stirring until the butter splits an the solids become a caramel color brown. Pour the brown butter into a small bowl and cool in the fridge until solid.

Once the brown butter has solidified, add the butter, cream cheese, powdered sugar, vanilla extract, and salt to a medium mixing bowl. Use a hand mixer to whip gently until smooth and free of lumps. There will be tiny specks in the creamy frosting, those are from the brown butter.