Combine instant coffee, sugar, and boiling water in the bowl of a stand mixer, or a bowl large enough to accommodate a hand mixer. Using the whisk attachment, whip ingredients at a high speed for 3-4 minutes, until stiff peaks form. The mixture will be very light in both texture and color.
Fill a mason jar with ice and fill 3/4 of the way with milk. Traditional whole milk is delicious, but use Homestead Creamery flavored milks to make it more decadent!
Top the milk with a dollop of the whipped coffee mixture. Please note this mixture is heavily caffeinated, so a little goes a long way! Stir with a spoon until nicely mixed and serve over ice with a straw.