1Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a large bowl, cream together the butter and brown sugar until smooth.
Beat in the egg and vanilla extract until well combined.
In another bowl, mix the rolled oats, all-purpose flour, and baking soda.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Drop spoonfuls of the dough onto the prepared baking sheet, spacing them about 2 inches apart.
Bake in the preheated oven for 10-12 minutes, or until the edges are golden brown.
Allow the cookies to cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.