Pour all ingredients into a small jar or container.
Using a milk frother, high speed blender, or whisk, froth for 15-20 seconds until frothy and foamed.
Notes
To make a large batch ahead: combine ½ cup heavy cream, ¼ cup whole milk, and ¼ cup syrup of choice in a large container and stir to combine. When ready to make cold foam, measure out ¼ cup of the mixture and froth!