Preheat the oven to 350°F (175°C).
In a large mixing bowl, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy.
Add the eggs one at a time, followed by the peppermint extract, and mix until combined.
In a separate bowl, whisk together the flour, baking soda, and salt.
Gradually add the dry mixture to the wet mixture, mixing until just combined.
Fold in the chocolate chips or chunks gently.
Drop rounded tablespoons of dough onto a prepared baking sheet, spacing them about two inches apart.
Bake for 10-12 minutes, or until the edges are lightly golden while the centers remain soft.
Remove from the oven and let them cool on the baking sheet for 5 minutes before transferring to a wire rack.
