First, heat the oven to about 200°C and prepare a muffin tin for about 12 muffins.
In a large bowl, mix the sugar, sucralose and lemon zest. Use your fingers to rub the zest into the sugar until the sugar is almost dissolved. Add the flour, chia seeds, baking soda, baking powder and salt and mix well. Leave to stand while we do the rest.
Next, in a medium bowl, whisk together the oil, yoghurt, watermelon juice and egg until thoroughly combined. Now add the cherries, lemon juice and vanilla essence.
4. Add the liquid mixture to the flour mixture. Stir gently until the flour is incorporated into the liquid. Pour evenly into 12 muffin tins and sprinkle a little sugar on top.
Bake for 15-17 minutes. Pierce with a toothpick and if it comes out clean it will be the sign that the muffins are ready. Remove from the oven and leave to rest for 5 minutes before unmoulding. It is important to let it cool; eating the dough hot can upset your stomach.