1Preheat the oven to 400 degrees F (200 degrees C). Grease a muffin pan with non-stick spray or line with paper muffin liners. Sift together the flour, baking powder, cinnamon and salt; set aside.
2In a medium bowl, cream together the sugar, margarine and egg with an electric mixer until light and fluffy. Mix in bananas, vanilla, cereal and dates. Blend in dry ingredients until just incorporated. Spoon into prepared muffin cups to about 2/3 full.
3Bake for 20 to 25 minutes in the preheated oven, until a toothpick inserted into the center comes out clean. Cool in pan over a wire rack for at least 10 minutes before removing muffins from the pan.