Preheat oven to 350° F. Cover 2 baking sheets with parchment paper or silpat mats.
Place rolled oats in blender or food processor and process until finely ground. Combine ground oats, flour, baking soda, salt and cinnamon in mixing bowl.
In another bowl, use an electric mixer to combine the butter, sugars, vanilla, vanilla bean and lemon juice. Add the eggs, and beat until fluffy.
Stir the flour mixture into the egg mixture, blending well. Add the chips and nuts (if desired) to the dough and mix well. Using 1/4 cup of dough for each cookie, scoop round balls with an ice cream scoop and place 2½-inches apart on prepared baking sheets.
Bake until cookies are lightly browned, 16 to 18 minutes. Transfer to wire rack to cool completely. Store in a sealed container to keep them soft and chewy.
Notes
If you do not want to grind oats for this recipe, go ahead and use regular oats. Just make sure that you are using quick-cooking oats.