Preheat your oven to 350°F (175°C).
In a large mixing bowl, combine the softened butter, white sugar, and brown sugar. Beat until light and fluffy (2-3 minutes).
Add the egg and vanilla extract. Beat until well combined.
In a separate bowl, whisk together the all-purpose flour, baking soda, and salt.
Gradually add the dry mixture to the wet mixture. Stir gently until just combined.
Fold in the semi-sweet chocolate chips or chunks.
Drop rounded balls of dough onto a baking sheet lined with parchment paper.
Bake for 10-12 minutes, or until the edges are golden brown but the centers are still soft.
Allow to cool on the baking sheet for 5 minutes, then transfer to a wire rack.
