Churn according to the manufacturer's instructions.
Stir in the toffee bits.
Transfer to a freezer safe container. Freeze until firm enough to scoop, about 3-4 hours.
Notes
Egg Yolks: This recipe uses raw egg yolks. If you prefer, you can use pasteurized eggs or temper the ice cream base before churning. The risk of salmonella from properly handled eggs is very low, but use whichever method you are most comfortable with.Tempering: Temper the base by heating the cream, milk, sweetener, and banana until steaming. Slowly whisk about 1 cup of the hot mixture into the egg yolks, then return everything to the saucepan. Cook over medium heat, stirring constantly, until the mixture thickens enough to coat the back of a spoon (170-175°F). Cool completely before churning.