Milk options: Skim milk is the easiest milk to foam.  But if you would like a richer-tasting foam, you are welcome to use other types of cow’s milk (or half and half).  We also tested the foam with plain almond milk and oat milk, which worked fairly well but can very widely from brand to brand.  If using a non-dairy milk, I’d recommend trying a barista-blend (such as this one), which will foam up and hold its shape a bit better.

Sweetener options: I prefer to naturally sweeten this drink with maple syrup.  But feel free to experiment with any of your other favorite sweeteners (such as coconut sugar, brown sugar, or white granulated sugar) instead.

Pumpkin pie spice: If you don’t have a jar of pumpkin pie spice (either homemade or store-bought) on hand, you’re welcome to just substitute straight ground cinnamon instead.

How to create the foam with a handheld milk frother: For the first minute or so, I recommend holding the frother at a 45-degree angle, keeping half of the tip exposed and half submerged in the milk mixture, which will create a whirlpool with some large bubbles.  Then submerge the tip entirely until the foam at a 45-degree angle, and continue frothing the milk mixture for 1-3 more minutes, until it reaches a tight, smooth consistency.  (Frothing time will vary depending on your frother, type of milk used, type of sweetener used, etc.)

Make-ahead tip: If you would like to prep this coffee the night beforehand, just go ahead and make your cold brew.  Then stir together the pumpkin foam mixture and refrigerate in a sealed container until you’re ready to froth it up the next day.

Source: Thanks for the inspiration, Starbucks!