This root beer float doubles down on that delightful root beer flavor by integrating both homemade root beer ice cream and extra root beer to top it off.
In a medium saucepan, combine the milk and the cream. Bring to a low simmer. While you are waiting for the cream to simmer, beat egg yolks in a large mixing bowl. Slowly add sugar while mixing. Beat until mixture is light yellow and thick. Slowly pour hot milk mixture into the egg yolk mixture while beating constantly. Return the cream/egg mixture to the pan, add salt and cook over low heat until the mixture coats the back of a spoon. Remove from the pan from the heat. Add the vanilla and root beer extracts. Pour the ice cream base into a large bowl and cover with plastic wrap. Refrigerate until completely cool (2 to 4 hours or overnight).
Once the base is completely cool, pour the chilled mixture into an ice cream maker. Freeze according to the manufacturer's directions. Then, freeze the ice cream in a freezer safe container until firm.
Scoop the ice cream into tall glasses. Pour chilled root beer over the ice cream, and serve immediately.