Press cookie dough into a greased 12-inch pizza pan. Grill cookie in pan for 10 to 15 minutes or until edges of cookie are lightly golden and top is set but not dry. Remove from grill (cookie may puff and fall at this point).
Drizzle caramel topping over cookie. Sprinkle chocolate pieces and/or baking bits, and peanuts over caramel. Return pan to grill for 1 to 2 minutes more or until chocolate pieces soften. Remove from grill and cool on a wire rack.
To serve, top with sliced bananas and, if desired, drizzle with chocolate topping; cut into wedges. Makes 12 servings.