In a saucepan, whisk together the sugar, cornstarch, salt, and coffee.

Slowly whisk in the milk and cream.

Cook over medium to medium high heat stirring constantly until thickened. It takes about 10-15 minutes. The mixture needs to come to a bubble so the cornstarch can reach full thickening power.

Meanwhile, in another bowl, whisk your egg yolk.

Add the vanilla bean paste.

Add a very small amount of the hot cream mixture to the egg yolk whisking constantly. Gradually add the rest being careful to not scramble the egg yolk.

Cover the ice cream with plastic wrap, having the wrap touch the surface so a skin does not form. Chill for a few hours, overnight if possible.

Freeze the mixture according to the directions used for your ice cream maker. A few minutes before the end of the freezing time add almost all of the Heath Bars. Leave a few for garnish.

Transfer the mixture to another container and garnish with the remaining Heath Bars. Freeze for at least two hours before you serve it.