Start by putting the lemon zest and the sugar in a smallish bowl. Rub the zest into the sugar using your fingers for a couple of minutes. Keep aside.
Lightly whisk together the flour, baking powder, baking soda and salt in a large bowl.
Whisk together the egg, melted butter, ricotta, milk, lemon extract and the lemon sugar, adding the lemon juice last, in a medium sized bowl till smooth.
Add the wet ingredients to the dry ones, and mix together in a folding motion. Do not over mix. Fold or stir everything together till just mixed. Over mixing will produce very dense and chewy muffins.
Using a large spoon or ice-cream scoop, fill each paper lined muffin cup with batter to just under 3/4th full each. Sprinkle the top of each with granulated sugar or drizzle with glaze after baking.
Bake at 200C (400F) for about 20 minutes till they’re done. These muffins are pale so do not brown or they will over bake. Remove from oven and remove each muffin from the cup. Cool completely.
If drizzling with glaze, mix together some icing sugar with about a tsp or two of lemon juice and some lemon zest. Mix till smooth and of reasonably thick but pouring consistency. Drizzle on the muffins and let it dry before serving or storing.