Cool It! (Spiked Watermelon Cooler)

Some of you have been asking for more fast, easy recipes on 6 Bittersweets -- and such you shall receive! Today watermelon cooler is very simple to make and inspired by a favorite childhood drink. Though the term "watermelon juice" will probably just make you furrow your brow in confusion, it's actually a drink widely available in restaurants throughout China. Made purely of blended and strained watermelon chunks, this juice has got to be one of the most refreshing things on a hot summer day.

The major (for serious) heat wave we've had in the D.C. area lately inspired to make this grown-up watermelon juice cooler. Don't tell anyone, but I actually intended this to be a frozen drink (and still included directions in case you prefer it slushy). But alas, I ran out of time and didn't get to fully freeze the melon. Perhaps it was for the best as this version is even closer to the beloved drink of my memories of China. Of course it didn't have vodka back then, but I think spiking this juice only made it better ^__^.

Spiked Watermelon Cooler/Slushie [Printable Recipe]
Serves 4 to 6

6 cups cubed seeded watermelon, 3/4-inch cubes
1 Tbsp freshly squeezed lemon juice
1 tsp freshly grated lemon zest
1 cup tonic water
1/2 cup vodka (optional)
6 Tbsp powdered sugar, or more to taste

If making into a slushie, place chunks side by side on a large baking sheet, so that they're not touching one another. Freeze at least 2 hours. Then puree melon cubes (frozen or not) with the remaining ingredients in a conventional blender or using a stick immersion blender. Taste and add more powdered sugar, if desired. For slushie, pour into glasses or small bottles and serve immediately. For non-frozen drink, pour into a pitcher and chill well before serving.