Add butter and brown sugar to large mixing bowl or the bowl of a stand mixer and beat until very creamy, about 5 minutes.
1 cup unsalted butter, 1 cup brown sugar
Add eggs, one a time, beating well after each addition. Mix in vanilla extract until well combined. Set aside.
2 large eggs, 2 teaspoons vanilla extract
Combine oats, all purpose flour, ground cinnamon, baking soda and salt in a large bowl and stir or whisk to combine.
1 ⅔ cup all-purpose flour, 1 teaspoon baking soda, 1 teaspoon ground cinnamon, ½ teaspoon salt, 2 ¼ cups old fashioned oats
Stir the dry ingredients in with the butter mixture just until combined.
Fold in cranberries and chopped walnuts.
1 cup dried cranberries, ½ cup chopped walnuts
Cover the dough tightly and chill for one hour in the refrigerator. (If you need to chill the dough for more than an hour, pre-scoop the cookies onto a baking sheet and cover with plastic wrap before placing in the fridge.)
Preheat the oven to 350°F. Line two large baking sheets with parchment paper or a silicone baking mat.
Scoop the dough using a 1.5 tablespoons scoop and place on the prepared baking sheets. Using the back of the scoop, a spoon or your fingers, lightly flatten the top of each cookie.
Bake cookies for 10 to 12 minutes or until the cookies are set and slightly brown on the edges but still soft in the center.
Let the cookies cool for 10 minutes on the baking sheet before transferring to a cooling rack to cool completely.