Giant Peanut Butter Cup Stuffed with Reese's Pieces. This giant version of one of our favorite chocolate treats has a surprise inside -- crunchy-creamy Reese's Pieces. Follow these steps to create this dessert delight. 1. Spray a 9-inch tart pan with cooking spray. Melt the chocolate in the top of a double boiler (alternatively, use a heatproof bowl set over-- not in-- a pot of simmering water). Keep the chocolate warm over low heat until ready to use. 2. Add the peanut butter, confectioners' sugar, saltines, butter and salt to a large bowl and blend with an electric mixer on medium speed until well combined. Fold in the candy-coated peanut butter candy. 3. Pour half of the chocolate into the prepared pan. Freeze until the chocolate is set and hardened, about 10 minutes. 4. Spread the peanut butter mixture over the chocolate in the pan with an offset spatula, leaving a 1/2-inch border around the edge. Pour the remaining chocolate over the peanut butter, spreading it over the top so it drips into the open border and no filling is visible. Freeze until set, about 10 minutes. Serve at room temperature.