Unroll the pie crusts on a work surface. With a rolling pin, roll each crust lightly into a 12-inch round. With 3-inch round cutter, cut 24 rounds from crusts, re-rolling scraps as necessary. Press 1 pie crust round in the bottom and up the side in each of 24 ungreased mini muffin cups, so the edges of crusts extend slightly above the sides of the cups. Bake 5 to 7 minutes or until very light golden brown; cool. Reduce the oven temperature to 325 degrees.
ADD THE FILLING:
Cut the candy bars in half lengthwise; cut into 1/8-inch pieces; chop coarsely. Place the candy bar pieces in the bottoms of the cooled crust-lined cups, reserving some for garnish.
In a small bowl, beat the cream cheese and sugar with an electric mixer on medium speed until smooth. Beat in the egg until well blended. Add the sour cream and peanut butter, beating until the mixture is smooth. Spoon 2 teaspoons of the cream cheese mixture over the candy bar pieces in each tart. Bake at 325°F. for 15 to 20 minutes or until the center is set. Cool completely (about 30 minutes).
ADD THE TOPPING:
In a pyrex measuring cup, add the whipping cream. Heat in the microwave until bubbling. Remove and stir in the chocolate chips until melted and smooth. If necessary, return to the microwave for 30 seconds until hot enough to melt. DON'T OVERHEAT.
Place a dollop of chocolate ganache on top of each tart. Garnish with pieces of Snickers Bar. Refrigerate for 2 to 3 hours before serving. Keep any unused tarts refrigerated.