Mix boiling water, instant coffee granules, sugar, and vanilla extract in a cup. Stir until sugar is dissolved.
Put the coffee mixture in the freezer and let it cool for 5 minutes.
Add the coffee mixture, heavy cream, and ice cubes to a blender and blend for 1 minute until smooth.
Pour into a cup and enjoy!
Notes
Heavy cream: You can substitute with half and half, whole milk, or ice cream. If you use whole milk, replace the boiling water in Step 1 with whole milk as well.Won't blend? Try making a larger batch or use the blender's tamper to push the ingredients down.