Add all three ingredients to a large mixing bowl or a large jar.
Use a hand mixer, immersion blender with whisk, or milk frothing wand to whip the coffee into soft peaks. This will take around 3-5 minutes.
Add the whipped coffee to a small glass of cold milk or whatever other beverage you want to serve this with.
Notes
You can whip coffee by hand, with a whisk. This will take a lot more effort but can be done. It will likely take more like 5-8 minutes to get the creamy, frothy texture you want.
If you want to add a little more flavor to the whipped coffee, add a little cinnamon or a small splash of vanilla extract before mixing.
If you use a milk frothing wand, I like to whip the ingredients in a large jar, as it keeps any spray from the frothing contained.
Immersion blenders with a whisk attachment work the very best for single serving amounts IMO.