Preheat the oven to 350°F (175°C) and line a baking sheet with parchment paper.
Cream the butter and sugar together in a mixing bowl until light and fluffy.
Add eggs and vanilla extract, mixing until fully combined.
Whisk together flour and baking soda, then gradually fold into the wet mixture.
Stir in rolled oats (and optional ingredients like raisins or nuts).
Scoop cookie dough onto the prepared baking sheet, leaving space between each cookie.
Bake for 10–12 minutes or until the edges are lightly golden.
Cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.