Add the whipping cream and vanilla extract to the bowl of a stand mixer, and beat on high speed until stiff peaks form.
Carefully fold in the sweetened condensed milk and matcha powder until they're well incorporated.
Pour the ice cream base into a 9x15-inch loaf pan, and smooth it out. Cover it with a layer of plastic wrap pressed against the ice cream, and freeze for 3 hours.
Remove the ice cream from the freezer, and put it back into the bowl of the stand mixer. Beat on medium-high speed for 1 minute.
Put the ice cream back in the loaf pan, smooth it out, and cover it again with plastic wrap pressed into the ice cream. Freeze for 5 more hours, then serve.
Notes
This ice cream will last in the freezer for 2 weeks. For best results, transfer the ice cream to an airtight container, and place a tight layer of plastic wrap against the top of the ice cream. Then put the lid on the container, and place it in the freezer.
To make this recipe vegan, replace the condensed milk with dairy-free sweetened condensed milk, and replace the whipping cream with coconut milk solids. To get coconut milk solids, chill coconut milk in the fridge, then discard the liquid.