Using a hand or stand mixer, blend together melted butter and sugars until smooth.
Beat in egg and vanilla.
Mix in baking soda and salt.
Add flour in small batches until everything is combined.
Fold in chips
Chill the dough in the refrigerator for at least an hour.
Line a cookie sheet with parchment paper and drop dough out by rounded tablespoonfuls spaced 2 inches apart.
Bake at 350° for 10-12 minutes. Do not overbake!
Remove from oven and let sit on the cookie sheet for one minute.
Then, transfer to cooling racks and let cool and firm up for at least an hour.