Heat oven to 375°F (350°F for dark or nonstick pan). Place paper baking cup in each of 24 regular-size muffin cups. In large bowl, beat cake mix, oil, water, 1 teaspoon rum extract, the pineapple and eggs with electric mixer on low speed 30 seconds. Beat on medium speed 2 minutes, scraping bowl occasionally. Divide batter evenly among muffin cups.