Low-carb cinnamon apples with vanilla sauce

Name: Low-carb cinnamon apples with vanilla sauce
Prep time: 20 min
Cook time: 20 min
Total time: 40 min
Yield: 6
Ingredients: 2 1/2 cups heavy whipping cream; 1/2 teaspoon vanilla extract; 1 star anise (optional); 5 tablespoons butter; 1 egg yolk; 3 apples, preferably a type that is firm and tart, for example Gravensteiner or Granny Smith; 1 teaspoon ground cinnamon