tablespoons creamy or chunky peanut butter, divided
(2-ounce) white chocolate baking bars
Line 8-inch square pan with foil; lightly grease foil. Melt semisweet chocolate and 2 tablespoons peanut butter in small saucepan over low heat; stir until melted and smooth. Pour chocolate mixture into prepared pan. Let stand 10 to 15 minutes to cool slightly.
Melt white chocolate and remaining 1 tablespoon peanut butter in small saucepan over low heat. Drop spoonfuls of white chocolate mixture over semisweet chocolate mixture in pan.
Using small metal spatula or knife, swirl chocolates to create tiger stripes. Freeze about 1 hour or until firm. Remove from pan; peel off foil. Cut or break into pieces. Refrigerate until ready to serve.