Mix together flour, sugar, eggs, baking powder, vanilla and margarine with a wooden spoon. Batter will be soft. Spray pan (8x8). Cut apples into chunks. Spoon half of the batter into pan and spread half of the apples on top. Sprinkle cinnamon on top of apples. Spoon in the other half of batter and the rest of apples. Reapply cinnamon to the top.
Recipe by mommy's two cents at http://mommystwocents.com/2011/09/nana-jeans-two-cents/