Preheat oven to 350 degrees.
Combine ricotta cheese, cream cheese, Splenda, egg, melted butter, 3 Tbsp. chocolate syrup and vanilla in a blender, until smooth.
Pour mixture into pie pan.
Add the final 1 tbsp. chocolate syrup in divided amounts over cheesecake.
Use a butter knife to swirl in the chocolate for desired look.
Bake 35-40 minutes or until almost set Turn oven off; let stand in oven 30 minutes with the door partially opened.
Remove cheesecake from oven; cool in pan on wire rack.
Cover and chill for 1 hour prior to serving.
Total: 20SL, 1L