• Add the peanut butter powder, brown sugar substitute, and salt to the bottom of an espresso shot glass.
• Brew the espresso directly over the top and stir until the powder has completely dissolved and there are no dry pockets left on the bottom. A handheld frother does this in about five seconds.
• Fill a glass with ice, then pour the milk over the top and give it a gentle stir. Then add the espresso mixture.
• Top with the marshmallow cold foam below, and drink it before the foam settles.

Marshmallow Fluff

• Put the marshmallow fluff and the tablespoon of milk in a jar or small glass and stir until the fluff loosens up and thins out. Skipping this is the number one reason marshmallow cold foam fails, because fluff straight from the jar is too sticky to froth and it will just ball up on the whisk.
• Add the heavy cream and the vanilla extract.
• Froth with a handheld frother until it thickens and holds a soft peak, about 20 to 30 seconds. A mason jar with a tight lid and 45 seconds of shaking gets you most of the way there.
• Spoon it over the top of the latte.