01 - Preheat oven to 350°F. Line two baking sheets with parchment paper.
02 - In a medium bowl, whisk together the flour, oats, baking soda, salt, and cinnamon.
03 - In a large bowl, beat the butter, granulated sugar, and brown sugar until light and creamy, about 2 minutes.
04 - Add the egg and vanilla extract to the butter mixture and beat until fully combined.
05 - Gradually add the dry ingredients to the wet mixture and stir until just combined.
06 - Fold in the dried cranberries and walnuts if using, ensuring even distribution.
07 - Drop rounded tablespoons of dough onto the prepared baking sheets, spacing them about 2 inches apart.
08 - Bake for 10 to 12 minutes until edges are golden and centers remain soft.
09 - Allow cookies to cool on the baking sheets for 5 minutes, then transfer to a wire rack to cool completely.