Preheat oven to 350°.
To prepare muffins, lightly spoon 1 1/2 cups flour into dry measuring cups; level with a knife. Combine 1 1/2 cups flour and next 5 ingredients (through salt) in a large bowl, stirring with a whisk. Make a well in center of mixture. Combine milk and next 7 ingredients (through egg white); stir well with a whisk. Add milk mixture to flour mixture, stirring just until moist. Fold in 1/4 cup coconut. Place 12 muffin cup liners in muffin cups; coat liners with cooking spray. Divide batter evenly among muffin cups.
To prepare topping, combine 1/4 cup coconut, 3 tablespoons flour, 3 tablespoons granulated sugar, and 1 tablespoon oil in a small bowl; stir with a fork until crumbly. Sprinkle topping evenly over batter. Bake at 350° for 23 minutes or until a wooden pick inserted in center of a muffin comes out clean. Cool in pan on a wire rack 15 minutes.