Preheat oven to 350 degrees
Spray a 9 x 5 inch loaf pan with non stick cooking spray and set aside.
In a large bowl, whisk together the eggs, sour cream, sugar, and vegetable oil until smooth
Zest lemon into the mixture, and stir in lemon extract
In a separate bowl combine all purpose flour, oat flour, and baking powder and salt, and stir to combine
Combine wet and dry ingredients, until just mixed, will not be totally smooth
Pour into prepared baking loaf pan
Bake for 55 mins, or until toothpick inserted into the center comes out clean
If the top begins to brown too much, tent with foil
Let cool completely before slicing