1. Heat oven to 350°F. Grease 9-inch springform pan.
2. Beat 1/2 cup sugar and butter in large bowl. Add 1 egg and 1 teaspoon vanilla; beat until creamy. Gradually add flour and baking powder, beating until smooth; stir in 1/2 cup small chocolate chips. Press mixture onto bottom of prepared pan.
3. Stir together sour cream, remaining 1/2 cup sugar, remaining 2 eggs and remaining 1 teaspoon vanilla in medium bowl; stir in remaining 1/2 cup small chocolate chips. Pour over mixture in pan.
4. Bake 50 to 55 minutes until almost set and edges are lightly browned. Cool completely on wire rack; remove side of pan. Spread whipped topping over top. Cover; refrigerate. Just before serving, arrange strawberry halves on top of cake; garnish as desired. Cover; refrigerate leftover dessert. Makes 12 servings.