Pre-heat oven to 350 °F (175 °C). Line 6 regular size muffin cups with paper foil liners.
Blend cream cheese and ricotta in a food processor until creamy. Add sugar substitute, egg, egg yoke, vanilla and process until smooth.
Divide 1 cup of batter among the 6 muffin cups. Add cocoa powder to the remaining batter and combine. Drop a heaping tablespoon of the cocoa batter into each muffin cup and gently fold to form a swirl.
Place the muffin tin in a large roasting pan and fill the pan with hot water to reach half way up the muffin tin. This is called a bain marie.
Bake until the cakes are puffed and set, 18-20 minutes.
Remove from the bain marie and cool at room temperature.
Refrigerate until chilled, about 2 hours. Bon Appetite!
Note: based on recipe from the South Beach Diet, Quick and Easy Cookbook.
There are 131 calories in 1 serving of Mini Cocoa Swirl Cheesecakes.