Preheat oven to 350°F (metal pan) or 340°F (if using a dark or coated pan).
Mix melted/browned butter with both sugars until glossy and combined.
Whisk in egg + yolk, then vanilla.
Add salt, baking soda, and flour. Mix just until flour disappears — it’ll be thick.
Fold in chocolate chips.
Spread evenly into a greased 10x15 pan (you can line with parchment for easy removal).
Bake 15–20 minutes, until edges are golden and center looks just set. It should still jiggle slightly when you move the pan.
Cool in the pan for at least 30 minutes before removing or decorating.