Preheat oven to 300 degrees F.

Using a stand mixer, cream butter, sugar and brown sugar together on medium speed for two minutes, scraping down the sides of the bowl with a spatula, as necessary.

Add eggs, vanilla, and lemon juice, blending with mixer on low speed for 30 seconds. Increase the mixer to medium speed and beat for about 2 minutes, or until light and fluffy, scraping down bowl.

Turn off the mixer and add the flour, oats, baking soda, salt and cinnamon. Mix on low for about 45 seconds or until just combined. Don’t overmix.

Remove bowl from mixer and stir in chocolate chips and walnuts, if using.

Portion dough with a cookie scoop or spoon, about 3 tablespoons of dough per cookie, onto a baking sheet lined with parchment paper or a Silpat baking mat, about 2 inches apart.

Bake for 20 to 23 minutes, or until edges are golden brown and center is still soft.

Remove from oven and sprinkle with sea salt, if desired. DoubleTree doesn’t do this, but I do. Cool on baking sheet for about 1 hour.