-Chocolate Chips, melted Heat oven to 350'F. Line a 20 cm or 23 cm square baking pan with foil, extending edges over sides of pan. In a small mixing bowl, beat butter, half cup sugar and salt until smooth. Stir together flour and cocoa; gradually add to butter mixture, beating until soft dough is formed. Press dough onto bottom of prepared pan. Beat cream cheese and remaining half cup sugar until smooth. Add eggs and vanilla; blend well. In separate bowl, mix 1 cup batter with topping, stirring until well blended. Pour 1 cup of topping-flavored batter over dough. Stir melted chocolate into remaining flavored batter. Drop tablespoonfuls of reserved flavored batter over top, gently swirl with knife or spatula for marbled effect. Bake 35-40 minutes or until cheesecake is firm and top is slightly puffed. Cool completely in pan on wire rack; refrigerate. To serve, lift from pan using foil edges, cut into squares. Garnish as desired. About 20 squares.