• Slice a thin wafer off of the top and bottom of the watermelon; just remove enough for it to sit without rolling. Slice the watermelon in half midway between the two wafers you removed.
• Work with one side of the watermelon at a time. This will yield two single serve cocktails.
• Use a paring knife to cut a straight line about ⅓ of the way across the cut side of the watermelon and about 2-inches down. This is going to be the “platform” where your mini bottle of alcohol will be held.
• Now use the melon baller or spoon to scoop out the remaining ⅔ of the watermelon. Be sure to leave any juices in the watermelon.
• This should leave ⅓ of the watermelon intact. Carefully scoop the under side of that ⅓ of the watermelon with your melon baller or spoon to create a 2-inch thick shelf.
• Now use the small end of your melon baller to cut a hole in the shelf. The hole should be as far from the cut edge as you can comfortably make it. Invert your lidded alcohol bottle to be sure the hole is the right size to allow the opening of the bottle to fit in the hole you’ve made.
• If you need to, widen the hole a little with your melon baller to accommodate just the opening and neck of the bottle. Now use the melon baller or a sharp knife to carefully create an opening on the underside of the shelf so that when you up-end the alcohol bottle, it will flow into the empty part of the watermelon.
• Fill the emptied side of the watermelon with watermelon balls and blackberries. Smack 2 mint leaves and tuck them among the fruit.
• Repeat this with the other watermelon half.
• You can now finish making your cocktails or place the prepared watermelons on a rimmed sheet pan, drape with plastic wrap, and refrigerate for up to 6 hours before serving.

To Finish Preparing Your Watermelon Cocktail:

• Squeeze 2 lime wedges per watermelon half over the melon balls. Pour a shot of orange liqueur into each watermelon half.
• Open the mini bottle of alcohol and carefully insert it into the opening in the watermelon that you created for it. The alcohol should flow freely into the watermelon.
• Pour enough chilled carbonated mineral water or plain seltzer in on top of the berries and watermelon that the bubbles rise to within ¼-inch of the rim of the watermelon. Garnish with another mint leave or sprig and 2 more lime wedges.
• Repeat this with the other watermelon half.
• Serve with a straw and, if desired, a spoon or fork to eat the fruit when you’re done sipping!