In a bowl, combine chocolate wafers, sugar and melted butter, tossing to coat. Place a tablespoon of crumb mixture into the each cup. Gently press down with your spoon. Place pan in the freezer while you prepare the filling.
In the bowl of a stand mixer, beat cream cheese until creamy. Add brown sugar and sour cream and continue to beat until light and fluffy. Add peanut butter. Stir in eggs and vanilla and continue to mix until fully incorporated.