In small blender or food processor, puree 3/4 cup watermelon. Put remaining 1/2 cup of watermelon on freezer and freeze until frozen, at least one hour.
Combine vodka, simple syrup, lime juice, and watermelon puree in cocktail shaker with ice. Shake vigorously for 30 seconds.
Place frozen watermelon cubes in mug and top with vodka mixture. Top with ginger beer and mint.
Notes
You can make your own simple syrup by heating together 1 cup of sugar and 1 cup of water until the sugar is dissolved. Take off heat and cool completely.
Perfect Pairing
Serve these mules with a bit of chicken wings as a fun party app.
[embed_recipe id='15581']