In a medium mixing bowl stir together the butter, peanut butter, and powder sugar. Once its is completely combined stir in the m&ms just until combined.
Take scoops about a tablespoon size and roll them into balls. Place them on a parchment-lined sheet pan. Place the peanut butter balls into the fridge for thirty minutes.
In a microwave safe bowl, melt the chocolate chips and shortening at thirty-second intervals until fully melted. Be carefully not to overheat the chocolate.
Place your cold peanut butter ball into the melted chocolate, use a fork to move the ball in the chocolate so it's completely coated.
Scoop the ball up with the fork and tap it on the side of the bowl to remove excise chocolate.
Using another fork push the ball off the fork onto a parchment lined sheet pan.
Top the ball with some m&ms. Repeat this with each peanut butter ball.
Place the balls in the fridge for thirty minutes, then enjoy.