For slump, stir flour, sugar, coconut, lime zest, baking powder and salt together. Whisk milk, egg yolk and melted butter and stir into flour until combined, but not necessarily smooth (like pancake batter, a few lumps are OK). Whip egg white until it holds a medium peak (white has a bend when whisk is lifted) and fold into batter. Spoon batter over fruit, leaving gaps for fruit juices to cook through and bake for 20 to 25 minutes, until slump has browned and fruits are bubbling. Allow to cool for at least 15 minutes before serving.