Combine graham cracker crumbs, melted butter, and 1 tablespoon sweetener; press on bottom and up sides of a 10-inch springform pan coated with cooking spray.
Bake at 350° for 10 minutes. Remove from oven. Wrap outside of pan with heavy-duty aluminum foil.
Beat ricotta cheese, cream cheese, and sour cream at medium speed with an electric mixer until smooth. Add 3/4 cup sweetener, flour, 2 1/2 tablespoons lemon juice, and vanilla, beating until blended. Add eggs, 1 at a time, beating until blended after each addition. Pour batter into prepared pan. Pour water to a 1-inch depth in a broiler pan. Place springform pan in water pan.
Bake at 350° for 25 to 30 minutes. Turn oven off. Let cheesecake stand in oven 1 hour. (Do not open oven door.) Remove springform pan from water pan; remove foil from springform pan. Cool cheesecake in pan at room temperature 4 hours. Cover and chill 8 hours.
Combine 1/2 cup water, next 4 ingredients, and remaining 1 tablespoon lemon juice in a small saucepan; bring to a boil, whisking constantly. Boil 1 minute or until thickened, whisking constantly. Remove pan from heat, and cool completely. Stir in strawberries. Serve over cheesecake slices.
Note: For testing purposes only, we used Splenda Granular for no-calorie sweetener and Land O' Lakes Light Butter for light butter.