Preheat the oven to 350 degrees.
Cream together your butter and sugars in a large bowl until light and creamy.
Mix in the vanilla and eggs.
Dump in the baking soda, salt, cocoa powder, and flour and stir together until everything is mixed.
Fold in the reeses pieces and peanut butter cup pieces.
Scoop cookie dough by the tablespoonful onto a lined baking sheet or sprayed with nonstick spray.
Bake cookies for 7-9 minutes until they start to look done.
Allow cookies to sit on the cookie sheet for about 3 minutes before removing to a cooling rack.