Preheat oven to 350 degrees. Spray inside bottom of a jelly roll pan or 13x9 dish with cooking spray. Mix sugar cookie mix, butter and egg in a large bowl until a soft dough forms; press evenly into a prepared pan. Bake in the preheated oven until crust is light golden brown, 10-15 minutes. Cool completely, about 30 minutes.
Beat cream cheese using an electric mixer on medium speed in a bowl until smooth. Add 8 oz. whipped topping and stir until smooth; spread over crust. Refrigerate.
Mix sugar and cornstarch together in saucepan; add 1 cup strawberries, water and vanilla. Cook and stir mixture, mashing strawberries with spoon while cooking, over medium heat until strawberries are softened and mixture is thickened, 10-15 minutes.
Stir food coloring into strawberry mixture and remove from heat; cool for 10 minutes. Gently stir remaining 3 cups strawberries into strawberry mixture; spoon over cream cheese filling. Top with whipped topping as desired. Refrigerate until set, about 1 hour. Serve within 4 hours.