Preheat oven to 180C (fan) and line a 12 hole muffin tray with paper cases.
In a bowl sift the flour, bicarbonate of soda and pinch of salt.
In a separate larger bowl mix together the yogurt, sugar, egg, grated apple, pecan nut and cinnamon.
Add the dry flour mixture from the first bowl to the larger bowl and fold the ingredients together.
Spoon the muffin mixture into the muffin trays, just enough mixture to fill ¾ of each hole.
Bake for 15 – 20 minutes in the centre of an oven until risen and brown. Check the centre of one with a wooden skewer to ensure it comes out clear, and is therefore cooked through.
Allow to cool a little in the muffin trays and then transfer onto a wire rack.
Once cooled mix the icing sugar with the water and spoon over the top of each muffin equally.