Sift together the flour, sugar, salt, baking soda and baking powder. In a large bowl, whisk together the egg, buttermilk, milk and melted butter. Add the dry ingredients. Stir until the flour disappears, being careful not to overbeat the batter.

Preheat the oven to 200 degrees F. Melt 1/2 tablespoon of the butter in a large castiron skillet over medium heat. Ladle about 1/4 cup of batter into the pan for each pancake. Immediately press 4 or 5 banana slices into each, so the batter oozes slightly over the fruit. Cook until bubbles appear and then flip and cook on the other side, about 3 minutes total. Transfer the pancakes to a platter and keep warm in the oven while you cook the remaining batches, adding butter to the pan as needed. Serve hot with warm coconut syrup.