Preheat oven to 375°F (190°C) with a rack in the center position.
Cream the softened butter with both sugars until light and fluffy.
Beat in the egg and vanilla until smooth.
Stir in flour, baking soda, and salt just until combined.
Stir in chocolate chips and nuts if using.
Scoop dough into rounded tablespoon balls, spaced 2 inches apart on a baking sheet.
Bake one sheet at a time for 10-12 minutes until edges are golden and centers are soft.
Cool on the tray for 3 minutes, then transfer to a wire rack.