Dawnalin: To begin, let forgo any scheme to make at-home versions of Reese's cups. If you like 'em, then buy 'em!
Several years ago, I created a peanut butter cake with milk chocolate mousse & peanut butter icing. Alas, it would require a lot of typing to enter the quite-lengthy method steps.
However, I have two more feasible suggestions for you: Consider making peanut-butter penuche glazed with a sheen of dark chocolate OR turn out a batch of Chocolate-Peanut Butter Brownies:
4 ounces unsalted skinless peanuts
4 ounces unsalted butter, softened
2 ounces unsweetened chocolate, coarsely chopped
1 large egg
1 cup packed dark-brown sugar
1/3 cup chunky peanut butter (I use a sugarless brand)
1½ tsp vanilla extract
2/3 cup flour
½ tsp baking powder
¼ tsp salt
4 ounces milk-chocolate pieces
350° oven. Lightly grease 8" square pan with shortening; line bottom & two sides with one length of aluminum foil that extends 2 inches over each side; lightly grease the foil.
In small dry skillet over low heat, lightly toast peanuts, shaking the pan frequently about 5 minutes). Cool the nuts, then coarsely chop them.
In small saucepan over low heat, melt 1 ounce butter. Remove from heat, add chocolate and allow it to melt.
Cream remaining butter; add brown sugar & egg, beating until light in color. Add peanut butter, melted choc/butter mixture, and vanilla; heat until blended.
Add flour, baking powder, and salt; beat quickly, just until blended. (Batter will be stiff). Stir in toasted, chopped nuts and the milk chocolate pieces. Scrape batter into baking pan, smoothing top. Bake brownies for about 30 minutes. Cool in pan on wire grid. Chill brownies for 20 minutes before removing from pan by using the extending foil to pull them out of the pan. Peel off the foil and cut the brownines into squares.