Mix OREO Small Pieces and butter; press about 2-1/4 cups onto bottom of each of 4 (9-inch) springform pans (or onto bottom of 1 pan for trial recipe). Bake in 300ºF-convection oven 10 min. Cool slightly. Spread 3/4 cup NUTTER BUTTER Variegate onto each warm crust. Refrigerate 15 min.
Beat cream cheese in large bowl of mixer fitted with paddle attachment until creamy. Blend in dulce de leche; carefully spread 1-1/2 cups over Variegate in each pan. Top with OREO Medium Pieces and nuts.
Mix chocolate and remaining Variegate; drizzle over pies. Refrigerate several hours or until chilled.