01 - Preheat oven to 350°F.
02 - Mix graham cracker crumbs, melted butter, and sugar until mixture resembles wet sand.
03 - Press mixture evenly into bottoms and sides of 6 mini tart pans.
04 - Bake for 8-10 minutes. Let cool completely.
05 - Purée watermelon, lime juice, and honey until smooth. Strain to remove pulp.
06 - Beat cream cheese until smooth. Add sweetened condensed milk, heavy cream, lemon zest, and lemon juice. Beat until light and creamy.
07 - Pour lemon cream into cooled tart shells, spreading evenly.
08 - Spoon thin layer of watermelon purée over lemon cream. Lightly swirl with skewer for marbled effect.
09 - Freeze for at least 3 hours or until set.
10 - Let sit at room temperature for 10 minutes to soften. Garnish with mint, watermelon balls, and extra lemon zest.