Preheat Oven: Set oven to 350°F (175°C) and line baking sheets with parchment paper.
Cream Butter and Sugars: In a large mixing bowl, beat butter, brown sugar, and granulated sugar until light and fluffy.
Add Wet Ingredients: Mix in eggs, vanilla extract, and lemon zest until combined.
Combine Dry Ingredients: In a separate bowl, whisk flour, baking soda, cinnamon, and salt. Gradually add to the wet mixture.
Fold in Oats and Mix-Ins: Stir in oats, cranberries, and walnuts until evenly distributed.
Scoop and Bake: Drop rounded tablespoons of dough onto prepared baking sheets, spacing about 2 inches apart. Bake for 10–12 minutes, or until edges are golden but centers remain soft.
Cool: Let cookies cool on the baking sheet for 5 minutes, then transfer to a wire rack.
Serving and Storage Tips
