No Bake Chocolate Peanut Butter Bars

I made these at the end of the school year for an AP chemistry food day. They were so good my chemistry teacher, who usually doesn't eat too much on food days had two bars! This summer has been incredibly busy, but I'm hoping to seize these last couple of weeks and finally get back to cooking again.

"I am a Rock" Simon and Garfunkel 

Adapted from Our Best Bites

Ingredients:

1 1/2 C graham cracker crumbs (or ginger snaps)
1 lb (3 1/2 C) powdered sugar
1 1/2 C creamy peanut butter
1 C (2 sticks) real butter, melted
1 12oz bag chocolate chips (milk, semi-sweet, or dark, you pick!)
2 tsp shortening

Directions:

In a large mixing bowl, combine graham cracker crumbs, powdered sugar and peanut butter and butter and beat until combined.  Press into a parchment (or waxed paper or foil) lined 9×13 pan.
Place chocolate chips and shortening in a microwave safe bowl and heat in 30 second intervals, stirring after each one, until melted and smooth.  Pour chocolate over peanut butter mixture and spread out evenly.  Place pan in the fridge just until chocolate is set and then cut into bars.  Tip:  If the bars chill until the chocolate is too hard to easily cut, use a sharp knife and score the cuts first, then gently cut through.  Can be stored in the fridge or at room temp.  They will stay firmer if stored in the fridge.