Whisk the egg whites until frothy (no need for stiffness). Sieve the flour, sugar and ground almonds into a bowl with a pinch of salt, then mix. Add the two melted butters, vanilla and egg whites, and beat lightly until you have a well-combined and smooth batter. Add in ¾ of the cherries, stir to combine, then pour into the tins. Top with the remaining cherries and bake for 25-30 mins until puffed and golden, and a skewer comes out clean.