Step 1

Add milk and simple syrup (and vanilla extract, if using) to a pitcher or narrow jar. Fully submerge the milk frother.

Step 2

Turn on the frother and froth until the milk starts to thicken, slowly pulling the wand towards the top of the milk. Froth about 15 to 20 seconds total, until the foam is thick and stabilized. Add to the top of cold brew, iced coffee, or an iced latte.