Heat oven to 360°F (180°C) and line a baking sheet with parchment paper.

In a mixer bowl with flat beater, cream the butter and sugars together until very light and fluffy, about 3 minutes.

Add egg and vanilla, beating until incorporated, and scraping down the bowl as needed.

Beat in salt fine sea or table salt and baking soda until combined, then the flour on a low speed until just mixed. Dough will look crumbly at this point.

With a spatula, fold in the chocolate chunks.

Scoop cookies with a cookie or ice cream scooper, spacing them apart on the prepared baking sheet. 

Bake for 9 to 12 minutes, until golden on the outside but still very soft inside. Let rest on the baking sheet for 5 minutes before transferring a cooling rack.