Preheat oven to 375°.
To prepare chocolate-chip cookies, lightly spoon flour into a dry measuring cup; level with a knife. Combine flour, soda, and salt in a small bowl; set aside. Beat sugars and butter in a large bowl until well-blended. Add water, vanilla, and egg whites; beat well. Add flour mixture; beat until well-blended. Drop by level tablespoons 2 inches apart onto baking sheets coated with cooking spray (you should get 20 cookies). Sprinkle chips evenly over dough. Bake at 375° for 8 minutes or until lightly browned. Cool 2 minutes or until cookies can be easily removed from pan; cool on wire racks.
Spoon 1/4 cup Banana-Maple Ice Cream onto each of 10 cookies. Top with the remaining cookies, pressing gently. Wrap sandwiches tightly in plastic wrap, and freeze until firm.