In a mixing bowl, combine the heavy cream, whole milk, sugar, and vanilla extract.
Whisk the mixture until the sugar is fully dissolved and the mixture feels smooth.
If you have an electric mixer, you can use it to speed up the process, but whisking by hand works too.
Pour the mixture into a freezer-safe container.
Cover with a lid or plastic wrap and freeze for 3-4 hours.
After the initial freeze, take the mixture out and stir vigorously with a spoon or whisk to break up any ice crystals.
Return the container to the freezer for another 4-5 hours or until fully set.
If you want to add mix-ins, stir them in after the ice cream has frozen to a soft-serve consistency, then return to the freezer.
When the ice cream is firm and scoopable, it’s ready to serve.