To make the chocolate crust shells:
Combine the flour, cocoa, sugar, and salt in a food processor until blended. Add the butter and shortening and blend until coarse crumbles form. Add the egg yolks and cold water and process with slow pulses until the dough forms a ball. Start with about 5 tablespoons of cold water, carefully keep adding a tablespoon at a time.
Refrigerate the dough for 30 minutes.
Next, preheat the oven to 350 degrees F.
Roll out your dough on a floured surface until it is about 1/8 inch thick. Then cut out the dough using a flour shaped cookie cutter. Once your first set of flowers or circles are cut, gently press the flowers into an ungreased mini muffin pan. Once your pan is full, bake for 12-15 minutes.Repeat until you have used as much of the dough cut out as possible.
Allow the shells to cool in the pan for 5 minutes before removing the crusts.
To make the peanut butter filling:
Beat peanut butter, cream cheese and vanilla until smooth. Then add the powdered sugar, beating again until smooth. Add in the Cool Whip and mix until well combined.
Place the filling into a piping bag or plastic bag, then pipe into the shells.
For the drizzle, melt the chocolate chips and shortening in a microwavable bowl (or in a double broiler). Allow the mixture to cool a few minutes, then transfer to a piping bag. Snip off a tiny portion of one corner of the bag and drizzle the chocolate onto the filled tart shells. Top with chopped peanuts.