Cream together 1 cup butter, 1 cup light brown sugar, and ½ cup granulated sugar until light and fluffy.
Add 2 eggs, one at a time, mixing until combined after each.
Stir in 1 teaspoon vanilla extract.
In a small bowl, mix together 1½ cups all purpose flour, 1 teaspoon baking soda, ½ teaspoon salt, ½ teaspoon ground cinnamon, and 3 cups old fashioned oats.
Mix into the butter mixture until just combined.
Fold in 1 cup dried cranberries and 1 cup dark chocolate chips.
Chill for at least 15 minutes.
Meanwhile preheat the oven to 350° F and line cookie sheets with parchment paper or silicone baking mats.
Scoop with a small cookie scoop onto prepared baking sheets.
Bake 8-10 minutes or until lightly golden and set.
Cool on the sheet for 5 minutes, then move to a wire rack to cool completely.
Store in an airtight container at room temperature for up to a week or two, or freeze for up to 3 months.