1 cup unsalted butter, softened 1 cup packed brown sugar 1/2 cup granulated sugar 2 large eggs 2 teaspoons vanilla extract 1 and 1/2 cups all-purpose flour
1 teaspoon baking soda 1 teaspoon ground cinnamon 1/2 teaspoon salt 3 cups old-fashioned rolled oats Optional: 1 cup raisins, chocolate chips, or chopped nuts
Preheat your oven to 350°F (175°C). Line baking sheets with parchment paper or silicone baking mats.
In a large bowl, cream together the softened butter, brown sugar, and granulated sugar until smooth and creamy.
Beat in the eggs one at a time, then stir in the vanilla extract. In a separate bowl, whisk together the flour, baking soda, cinnamon, and salt.
Gradually add the flour mixture to the butter mixture, mixing until just combined. Stir in the rolled oats and your choice of raisins, chocolate chips, or nuts.
Drop rounded tablespoons of dough onto the prepared baking sheets, spacing them about 2 inches apart.
Bake for 10 to 12 minutes in the preheated oven, or until the edges are golden brown.