Melt butter in a sauce pan over medium low heat.

Add the brown sugar and mix to incorporate.

Add the milk and vanilla and mix to combine. Bring the mixture to a simmer stirring constantly until the sugar is dissolved.

Remove from heat and add the peanut butter. Stir until the peanut butter is melted into the mixture.

Add confectioners sugar to a mixing bowl and pour the wet mixture over it.

Use a hand mixer, starting on low speed, to mix everything together. Increase speed until well incorporated. The mixture will become very thick.

Add the easy peanut butter fudge bar mixture to an 8 x 8 pan. I used a disposable foil pan but you could line a regular pan with parchment paper.

Cover and refrigerate for two hours to allow the fudge bars to set up.

Remove from the refrigerator. You can easily remove the entire set up fudge from the pan at this point. After removing, cut into squares.

Bag each bar into a holiday plastic gift bag and close with a twist tie. Finish with ribbon.