Step 1

Line an 8x8-inch baking pan with parchment paper and set aside.

Step 2

Add the powdered sugar to a large mixing bowl and set aside.

Step 3

In a medium-sized saucepan over medium heat, melt the butter. Then stir in the brown sugar and milk and bring it to a boil. Once boiling, allow to sit untouched for 1 minute and 45 seconds.

Step 4

Remove from heat, then stir in the peanut butter and vanilla extract until smooth and creamy.

Step 5

Pour the hot peanut butter mixture into the bowl with the powdered sugar, then beat with an electric mixture until completely smooth. Pour into the prepared pan and let sit until completely cooled and set.