In large bowl, add cream cheese and peanut butter. Using a hand mixer, beat together on medium speed until smooth. Add powdered sugar and vanilla and beat on low until combined. Fold in whipped cream, Reese’s Pieces, and Reese’s Peanut Butter Cups. Pour mixture into pie crust, and garnish with additional Reese’s Pieces and mini Peanut Butter Cups. Cover and freeze until firm, at least 3 hours and up to overnight. Slice pie and garnish with chocolate sauce before serving.