Grease the muffin baking tin with butter and dust with flour, tapping off the excess flour. Alternatively, you can line it with paper muffin cases.
Pour freshly squeezed lemon juice into a mixing bowl.
Core apples and cut them into small cubes, adding them to the lemon juice in batches and mixing gently each time. This will prevent the apple pieces from turning brown.
Beat eggs, honey and salt into a light, fluffy mixture.
Add soft butter cut into pieces and mix briefly.
Mix flour with baking soda.
Add the flour mixture to the honey mixture and mix briefly but vigorously to form a thick batter.
Fold the apple pieces into the batter.
Divide the batter between the muffin tins so that they are almost full.
Bake the muffins with apples in a preheated oven at 356 °F (180 °C) for approx. 15 minutes.
Leave the apple muffins to cool in the baking tin and then take them out.