Heat oven to 375°F. Remove pie crust from pouch; unroll crust on ungreased 15x10x1-inch baking pan. Spoon cinnamon apples evenly onto half of crust to within 1 inch of edge. Sprinkle 2 teaspoons of the cinnamon-sugar over apples.
Brush water over edge of crust. Fold untopped half of crust over apples; press edges with fork to seal. Cut three 1-inch slits in top. Sprinkle remaining 2 teaspoons cinnamon-sugar over top.
Bake 30 to 40 minutes or until top is crisp and golden brown. Immediately remove from cookie sheet; place on serving platter. If desired, serve with ice cream.