Step 1Cream butter with brown and granulated sugars until well blended. Stir in vanilla and egg. Fold in flour, baking soda, salt and last, chocolate chips.
Step 2Form dough into rounds slightly larger than golf balls and place 2 inches apart on baking sheets lined with parchment paper.
Step 3Bake at 350 degrees until just light brown around edges, 14 to 16 minutes (overbaking will make cookies hard). Cool on racks; cookies will crisp as they cool.