Refreshing Watermelon Rum Punch

3 lb. fresh watermelon
8 oz. white rum
6-8 T. fresh lime juice
¼ c. simple syrup
2 oz. Elderflower liqueur (such as St.-Germain)

1. Using a small paring knife, cut one end of melon in zigzag pattern. Discard end.
2. With a spoon, remove melon flesh and place in a blender. Process until smooth.
3. Pour through a fine-mesh strainer and discard solids.
4. Return 1 c. of melon juice to the cut watermelon rind. (Save remaining juice for another use.)
5. Add rum, lime juice, simple syrup and liqueur to the watermelon.
6. Stir to combine.
7. Top with ice and serve!