Preheat oven to 350°F (175°C) and line a baking sheet with parchment paper.
Whisk oats, flour, baking soda, and salt in a bowl. Set aside.
In another bowl, beat butter, brown sugar, and granulated sugar until creamy.
Add the egg, vanilla, and espresso powder. Mix until smooth.
Slowly fold in the dry ingredients, mixing just until combined.
Stir in chocolate chips if using (because why wouldn’t you?).
Scoop dough into small balls and place them on the baking sheet.
Bake for 10–12 minutes until golden brown but slightly soft in the center.
Let cool for 5 minutes before eating—if you can wait.
Enjoy with coffee, milk, or straight from the tray.