I always keep my half and half in the fridge until the moment I need it. Cold dairy froths up faster and holds more air than room-temperature dairy. If your half and half feels even slightly warm, pop it in the freezer for five minutes before you start.
Pour the half and half, pumpkin spice sauce, condensed milk, pumpkin pie spice, salt, and vanilla into your mixing cup. I like to give everything a quick stir with a spoon first so the frother doesn't have to work as hard to combine it all.
Insert your handheld frother and turn it on. I move mine in small circles near the surface for about 30 to 45 seconds. You'll notice the mixture doubling in volume and turning pale and airy right before your eyes.
I always stop frothing once the mixture is thick but still pourable, almost like softly whipped cream. If you keep going past this point, you risk turning it into stiff whipped cream instead of a smooth foam.
Spoon the foam gently on top of your iced coffee, cold brew, or chai latte. I like to pour slowly over the back of a spoon so it sits in a neat layer instead of sinking straight to the bottom.
Finish with a light dusting of pumpkin pie spice or cinnamon on top. I serve mine right away since the foam is at its fluffiest within the first few minutes.