1 cup sour cream
½ cup white sugar
¼ cup margarine
1 large egg
1 teaspoon rum flavored extract
1 ½ cups all-purpose flour
1 teaspoon baking powder
½ teaspoon baking soda
½ teaspoon salt
1 (15 ounce) can crushed pineapple, drained
½ cup flaked coconut
Preheat the oven to 375 degrees F (190 degrees C). Line a 12-cup muffin pan with paper liners.
Beat sour cream, sugar, margarine, egg, and rum extract in a large bowl with an electric mixer until smooth.
Whisk flour, baking powder, baking soda, and salt together in a medium bowl. Blend flour mixture into the wet ingredients. Stir in drained pineapple and coconut. Divide batter among the prepared muffin cups.
Bake in the preheated oven until the tops spring back when lightly tapped, 20 to 25 minutes.
Remove from the oven and cool on a wire rack.