Whisk together the plain flour, dessicated coconut, honey and melted butter.
Beat the egg whites until they are doubled in volume and hold a soft peak when the whisk is drawn through them. Add the caster sugar, and continue to beat until the egg whites are stiff and glossy.
Stir a tablespoon of the egg whites into the coconut mixture just to soften the mixture. Fold half of the egg whites into the mixture, gently lifting the mixture to incorporate them. Fold in the remaining egg whites.
Place a silicone mini muffin tin on a baking tray, or butter your muffin tin if it is not silicone. Fill each cup 3/4 full using a tablespoon.
Bake in the preheated oven until a skewer inserted near the centre comes out clean, about 10 minutes. Allow to cool for 5 minutes, then turn the muffins out of the tin to cool completely.
To freeze egg whites, pour one egg white into each compartment of an ice cube tray, and place in the freezer. When frozen, unmould quickly and place the frozen egg whites into a recloseable freezer bag.