Cut the butter into small slices first, then and Teddie Peanut Butter to a large mixing bowl and beat on medium speed until well combined and creamy. Cutting the butter first will help incorporate it into the peanut butter rather than adding the whole stick.
Next, add in the milk, extract, and powdered sugar. Reduce the hand mixer speed to low and cream all ingredients together until a nice fluffy consistency.⠀
If needed, add more milk to make it fluffy.
Optional: Let the frosting chill for an hour to firm up a little bit.
Then, transfer the frosting into a piping bag with a large piping tip of your choosing. Refrigerate any leftovers in an airtight container for up to a week (but let it reach room temperature before using).
Using any premade cupcake mix, we opted for yogurt and applesauce as oil and egg substitutions (however you can use the ingredients listed or use substitutions). We added 1 cup of Teddie Natural Smooth to the mix for extra flavor.