Step 1Heat the oven to 350 degrees. Combine the flour, sugar and sea salt in a mixing bowl and stir to mix.
Step 2Combine the coconut milk, orange juice, milk, rum and bitters in a 2-cup measuring cup. Add the egg yolks and whisk or stir to blend. Stir into the dry ingredients and mix until no lumps remain.
Step 3Beat the egg whites in a second bowl just until stiff peaks form. Gently but thoroughly fold into the batter. Scrape into a souffle dish or 1-quart casserole. Set the dish into a large baking dish and pour hot water in to a depth of about 1 inch.
Step 4Bake for 50 minutes. Serve warm.