Preheat the oven to 350°F (175°C). Line two large baking sheets with parchment paper and set aside.
In a large mixing bowl, beat the softened butter, brown sugar, and granulated sugar together for 2 to 3 minutes until the mixture becomes light, fluffy, and creamy.
Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract and mix until fully incorporated.
In a separate bowl, whisk together the flour, baking soda, and salt until evenly combined.
Gradually add the dry ingredients to the wet ingredients, mixing on low speed until just combined. Do not overmix.
Fold in the old-fashioned oats and dried cranberries using a wooden spoon or silicone spatula. Stir until evenly distributed throughout the dough.
Scoop approximately 2 tablespoons of dough for each cookie and place onto the prepared baking sheets, leaving about 2 inches between each dough ball.
Bake for 10 to 12 minutes or until the edges are lightly golden brown and the centers appear slightly soft.
Remove the baking sheets from the oven and allow the cookies to cool on the pan for 5 minutes.
Transfer the cookies to a wire rack and cool completely before serving or storing.