Pulse the oats in a food processor until fine; set aside

In a medium bowl, combine the oats, flour, baking soda, salt and cinnamon. Mix well.

In a large bowl, add the butter and both sugars. Beat with an electric mixer until fluffy. Add the the vanilla, lemon juice and eggs and mix until smooth.

Add the flour mixture to the wet ingredients and mix with a wooden spoon, being careful not to overmix. Stir in the chocolate chips and nuts.

Preheat oven to 350 degrees. Line 2 large baking sheets with parchment paper. Use a large scoop (3 tablespoons) to scoop dough onto the prepared cookie sheets. Place cookies in the refrigerator for 20-30 minutes.

Remove cookies from refrigerator and bake in the preheated oven for 10-12 minutes, or until firm and just beginning to brown on the edges. Do not overbake.

Cool for 5 minutes on the baking sheet before removing to a wire rack to cool completely.