Preheat the oven to 350 degrees Fahrenheit and prepare a baking pan with parchment paper or spray with non-stick spray.
Cream the butter and sugars together then add the egg and vanilla extract and mix until smooth.
Whisk the flour, salt, baking soda and baking powder together in a separate bowl.
Add it to the wet ingredients and stir until combined.
Add the chocolate chips and crushed peppermints and stir again until combined. **See note below about optional chilling time.
Use a cookie scoop or your hand to form 1 ½ inch balls from the dough.
Add six cookie balls to the pan spread one inch apart.
Bake for 7-9 minutes, or until the edges of the cookies turn a light golden color.
Remove from the oven and use a spatula to gently push the cookie edges in slightly for fuller cookies.
Once the cookies have cooled for 5-6 minutes, remove them from the pan and let them cool completely on a cooling rack.
Repeat the baking process with the remaining dough until all of the dough has been used, then serve.
NOTE ON CHILLING TIME: These cookies come out thin with crisp edges and soft centers if the dough is not chilled. If you prefer a thicker cookie, chill the dough for an hour before scooping into balls and baking.