Preheat oven to 350 degrees F (175 degrees C). Grease and flour 12 muffins cups or line with paper liners.
Beat sugar and margarine together in a bowl using an electric mixer until smooth and creamy; stir in eggs. Stir bananas into margarine mixture; stir in vanilla extract.
Whisk flour, baking powder, and salt together in a bowl; stir into margarine mixture until just combined. Fold oranges and coconut into batter. Spoon batter into muffin tins.
Bake in the preheated oven until a toothpick inserted in the center of a muffin comes out clean, 20 to 30 minutes.
