Bring the heavy cream, butter, and sweetener to a gentle boil and cook stirring frequently until it is light golden brown and thick enough to coat the back of a spoon. Remove from the heat.
Cool until room temperature before stirring in the egg yolk
OR, if you are impatient like me, very very stream the hot condensed milk into a bowl with the egg yolk while whisking like crazy.
Nutrition: This makes 6 servings. Each serving is approximately 2 tablespoons. There are 0.4 NET carbs per serving.To Store: Keep in an airtight container in the fridge for 5-7 days. To Freeze: It will last 3-4 months in the freezer if it's kept airtight. Glass or plastic containers both work well. Notes on Sweeteners: