Combine flour, sugar, baking powder, salt into a bowl and make a well in the center. In another bowl combine ricotta, water, olive oil, lemon juice & rind and the egg. Pour this mixture into the well. Stir until blended.
In a muffin pan sheet, place liners in each slot and lightly spray with cooking oil. Divide batter into each slot equally.
Bake for about 16 minutes. Test with a wooden tooth pick in the center, if it comes out clean, it is done cooking.