In a large bowl, cream the butter and sugar until light and fluffy. Beat in the egg, sour cream and extract. Combine the flour, baking powder, baking soda and salt; stir into the creamed mixture just until moistened. Fold in the pineapple, coconut and pecans.
Fill 12 greased or paper-lined muffin cups two-thirds full. Bake at 375° for 22-25 minutes or until a toothpick comes out clean. Cool for 5 minutes before removing from pan to a wire rack. Freeze option: Freeze cooled muffins in an airtight container. To use, thaw at room temperature or, if desired, microwave each muffin on high for 20-30 seconds or until heated through.
Test Kitchen Tips
If you don't like the flavor of rum, skip the extract or substutute vanilla or coconut extract.
If you want to get the most bang for your buck, try toasting nuts before adding them to recipes where they're mixed into a batter.
Full-fat Greek yogurt can swap in for the sour cream if you want to lighten these muffins up.