Blend all the ingredients (except the lemon zest) in the blender until well combined. Pour the liquid into a silicone muffin mold and freeze until solid.
Once frozen, pop out the pucks and add them to a blender. Blend on high for a few minutes until it becomes “snow.” Scrape down the sides and blend on high again until it becomes creamy. (You can speed up this process by adding a splash more of almond milk, but we found that adding more liquid caused the ice cream to melt quicker and become thinner.)
Scoop it into a bowl, top with lemon zest, and enjoy!