Cream butter and sugars in the bowl of a stand mixer on medium speed for 2 minutes. 8 ounces unsalted butter, ¾ cup + 1 tablespoon granulated sugar , ¾ cup packed light brown sugar
Add eggs, vanilla and lemon juice, blending with mixer on low speed for 30 seconds, then medium speed for 2 minutes, or until light and fluffy. Scrape the sides of the bowl as needed. 2 large eggs, 1 ¼ teaspoons vanilla extract , ¼ teaspoon freshly squeezed lemon juice
With mixer on low speed, add flour, oats, baking soda, salt and cinnamon, blending for about 45 seconds. Don’t overmix. 2 ¼ cups all-purpose flour , ½ cup old fashioned rolled oats , 1 teaspoon baking soda, 1 teaspoon salt , Pinch cinnamon
Remove bowl from mixer and stir in chocolate chips and nuts. 2 ⅔ cups semi-sweet chocolate chips , 1 ¾ cups chopped walnuts
Portion dough with a scoop (about 3 tablespoons) onto a baking sheet lined with parchment paper about 2 inches apart.
Preheat oven to 300°F. Bake for 15 minutes*, or until edges are golden brown and center is still soft.
Remove from oven and cool on baking sheet for about 5 minutes, then move to a cooling rack to cool completely.
