01 - Preheat oven to 350°F. Line two baking sheets with parchment paper.
02 - Whisk together flour, baking soda, cinnamon, and salt in a medium bowl.
03 - Using an electric mixer or whisk, cream the softened butter with brown and granulated sugars until light and fluffy.
04 - Beat in eggs one at a time, followed by the vanilla extract, mixing thoroughly after each addition.
05 - Gradually stir the dry ingredient mixture into the wet ingredients until just combined.
06 - Fold in rolled oats, dried cranberries, and chopped walnuts gently.
07 - Drop rounded tablespoons of dough onto the prepared baking sheets, spacing about 2 inches apart.
08 - Bake for 10 to 12 minutes, until edges turn golden and centers look set.
09 - Let cookies rest on baking sheets for 5 minutes before transferring to a wire rack to cool completely.