Preheat oven to 350 degrees. Grease a jumbo muffin pan or regular muffin pan.
In a large bowl, combine sugar, oil, and egg. Beat until smooth. Blend in banana and vanilla.
Mix together flour, baking powder, baking soda, salt, cinnamon and allspice. Stir into egg mixture just until moistened. Gently fold in the lemon zest, lemon juice, prunes and pecans.
Do Not Over Mix. Spoon into prepared muffin pan.
Bake for 25 to 30 minutes or until toothpick inserted comes out clean.