Heat oven to 400ÆF. Line eight 2-1/2-inch muffin pan cups with paper bake cups or generously spray cups with cooking spray.
In medium bowl, crush KELLOGG’S CORN FLAKES® cereal until the size of peas. Remove 1/4 cup and set aside for topping.
Add muffin mix, pineapple with juice, yogurt, and egg to bowl. Stir until just blended. Spoon batter into prepared muffin cups, dividing evenly. Sprinkle tops evenly with reserved crushed cereal.
Bake in 400ÆF oven for 15 to 16 minutes or until tops are light golden and wooden pick inserted in center of one or two muffins comes out clean. Cool in pan on wire rack 5 minutes. Remove muffins from pan to wire rack.