Step 1

In a blender, combine frozen and fresh watermelon and half the jalapeno. Blend until you don't see any jalapeño left.

Step 2

Strain mixture and discard pulp. Add lime juice and simple syrup and stir to combine.

Step 3

To make the salted rims, combine salt and cayenne powder in a wide flat bowl. Use a wedge of lime and run it around the edge of the glass, then dip the wet edges into the spicy salt.

Step 4

Pour glasses 2/3 full with mixture then top off with sparkling water. Garnish with a jalapeño coin and watermelon wedge and serve!