Preheat oven to 400.In a large bowl, sift together dry ingredients (flour through sugar). In a seperate bowl, wisk together wet ingredients (oil through vanilla). Fold wet into dry, halfway through mixing add lemon zest and distribute well.Spray muffin tins w/ non stick cooking spray. Fill each tin 2/3 full. Bake for 20-25 minutes, until a toothpick inserted in the center comes out clean. Serve warm.