Place butter and peanut butter into a sauce pan. Bring to medium heat and whisk until peanut butter and butter is melted. Remove from heat. Whisk in vanilla and salt.

Whisking well add powdered sugar. Switch to a spoon and keep mixing. This will be tough. Once the fudge is smooth and no pockets of sugar are visible then the fudge is ready to add to the pan.

Add parchment paper to the baking pan.

In a 9x9 pan, scoop the fudge ball into the pan. Flatten with clean hands. Then smooth the surface with a cake spatula or butter knife.

Place the fudge in the fridge for 24 hours or till set. Once set pull out and cut into squares.

Tips: In the peanut butter and powdered sugar process if the fudge does not get thick or is still oily add more powdered sugar by 1/4 cup at a time until it looks almost dry.