In a large mixing bowl, cream the butter, brown sugar, and granulated sugar until light and fluffy. Add the eggs and vanilla extract, mixing until well combined.
Whisk together the flour, baking soda, and salt in a separate bowl. Gradually add this mixture to the wet ingredients, mixing just until incorporated.
Gently fold the old-fashioned oats and chocolate chips until evenly distributed throughout the dough.
Cover the dough and refrigerate for at least 30 minutes to enhance flavor and prevent spreading during baking.
Set your oven to 350°F (175°C) and line baking sheets with parchment paper.
Scoop dough into evenly sized balls (about 2 tablespoons each) and place them 2 inches apart on the prepared baking sheets.
Bake for 10-12 minutes, or until the edges are golden brown but the centers remain soft.
Let the cookies cool on the baking sheets for a few minutes before transferring them to a wire rack. Serve warm or store for later enjoyment!