Melt the butter in a large saute pan or skillet (not a saucepan!) over medium heat.

Add powdered Besti and 2 cups of heavy cream. Bring to a boil, then reduce to a simmer. Simmer for 30-45 minutes, stirring occasionally, until the mixture is thick (like condensed milk), coats the back of a spoon and volume is reduced by half. It will also pull away from the pan as you tilt it. (This will go faster if you use a larger pan.)

Pour the condensed milk into a large bowl and allow to cool to room temperature. Stir in the vanilla extract.

Whisk the almond milk and remaining heavy cream, until smooth.

Chill the mixture in the fridge for at least 4 hours or overnight. (You can skip this step if you really want to, but the texture will be better if you chill it.)

Transfer the mixture to your ice cream maker and churn according to manufacturer's instructions, or until the ice cream is the consistency of soft serve. Mine takes about 20-25 minutes. (If you want to add mix-ins, add them toward the end of the churning process.)

Enjoy immediately, or for firmer, scoopable ice cream, transfer to a freezer container and freeze for 2-4 hours, until firm.

Transfer the mixture to a freezer container (like a 9x5 in (23x13 cm) loaf pan) and smooth the top with a spatula. Line the surface with a piece of parchment or wax paper to keep ice crystals from forming.

Freeze for 4-6 hours, until firm. Stir the ice cream during the freezing process, every 30 minutes for the first 2 hours and every 60-90 minutes for 2-3 hours after. (If you want to add mix-ins, gently stir them in after the first hour.)