Preheat the oven to 180°C.
Sift the flour into a mixing bowl, then stir in the salt and baking powder.
Spoon the cottage cheese into a mixing bowl, then add the melted butter, sugar, vanilla, eggs, lemon zest & juice. Combine well, then gradually stir in the flour mixture.
Fold in the sultanas, if used.
Spoon the mixture into a muffin tin, lined with paper cups, or into individual silicon cases.
Bake the muffins for 20-25 minutes.
Serve them with lemon icing, cream cheese frosting or just dusted powdered sugar.