Pineapple Banana Muffins

Preheat oven to 350 degrees. Line 12-cup muffin pan with cupcake liners; set aside. In medium bowl, combine flour, oats, baking soda, cinnamon, and salt; set aside. In large bowl, with electric mixer, beat butter and sugar until light and fluffy, about 5 minutes. Beat in eggs, one at a time, and vanilla until blended, scraping sides of bowl occasionally. Gradually beat in flour mixture, then bananas and pineapple, just until blended. Stir in the nuts. Spoon evenly into prepared muffin pan. Bake 25 minutes or until toothpick inserted in center comes out clean. Cool 5 minutes before removing to wire rack to cool completely. Freezes well.