If you’re using the oven, preheat it to 180°C (350 F).
Sift the flour into a bowl, then add the sugar, salt and baking powder. Gently combine.
In another bowl, mix the eggs, milk and oil. Add this to the flour gradually, while stirring constantly.
When the batter is smooth, mix in the lemon juice and zest.
Pour the batter into a muffin tin lined with paper cups or into silicon moulds. (Put the silicon cases on a baking sheet).
Bake for about 20 minutes in the middle of the oven or until an inserted skewer comes out clean.
Let them cool in the cases for 5 minutes, then carefully turn them out onto a wire rack.
Mix the lemon juice and some icing sugar to make a thin glaze.
Brush the muffins with the glaze while they’re warm, then let them cool.
Dust with icing sugar before serving.