Preheat oven to 180c or 350f
Add the yogurt, egg, sweetener, juice and rind of lemon to a bowl and whisk thoroughly.
Sieve in the flour, baking powder, baking soda and mix until all ingredients are combined.
Spray 8 muffin cases (or use a silicone muffin tray) with spray oil
Bake in oven until lightly golden and a skewer entered in the centre comes out clean (approx 30mins)
Pierce all over the top of the muffins with a small wooden skewer and allow to cool.
For the drizzle
Add the icing sugar to a bowl
Slowly add the juice of half a lemon, stirring after each little bit, until you have an icing that can be easily drizzle (not to thick, not too runny)
Once muffins have cooled, drizzle icing over the top.
These are great with some fresh fruit (especially raspberries)