In a metal bowl (large enough to fit over a pot to act as a double boiler), whisk together the egg yolks and sugar until the yolks become light yellow and thicker.

Fill the pot half way with water and bring to a simmer.

Add the milk and cream to the yolk and sugar mixture and whisk together well.

Put over the pot to act as a double boiler, and lightly whisk constantly until the mixture thickens.

Fold in the vanilla and Coca-Cola.

Put in the refrigerator until completely chilled.

Use the mixture in an ice cream maker (follow the directions for your model.)

Once the ice cream is finished in the maker, you can put it into a freezer safe container and pop it into your freezer to help firm it up if needed.