Cut the watermelon into manageable chunks, removing any seeds if necessary, and measure out about 4 cups of the chunks.
1 large ripe watermelon
Place the watermelon chunks into a blender and process until smooth and liquid. Taste and add honey or syrup if desired, blending briefly to combine.
1 large ripe watermelon, optional to taste honey or agave syrup
Pour the blended watermelon mixture into a lidded container or a shallow dish suitable for freezing. Cover tightly and place in the freezer.
1 large ripe watermelon
Let the watermelon mixture freeze for at least 4 hours, stirring every hour in the first two hours to break up ice crystals and promote an even texture.
1 large ripe watermelon
Once fully frozen and with a slightly chalky, firm texture, remove from the freezer and use a sharp knife to cut into slabs resembling slices of cake. Serve immediately for a cold, refreshing dessert.
1 large ripe watermelon