Position two racks in the upper and lower thirds of the oven and preheat to 350º. Line two baking sheets with parchment paper.
In a large bowl, whisk together the sugar and egg until combined. Whisk in the melted and cooled butter, then stir in the vanilla.
In a medium bowl, whisk or sift together the flour, baking soda and sea salt. Stir the flour mixture into the egg mixture until almost combined, then stir in the flaky salt, oats, nuts, chocolate chunks and nibs until just combined.
Drop the dough by heaping tablespoons (or use the purple-handled spring-loaded ice cream scoop) onto the lined baking sheets, spacing them at least 2 inches apart. Flick a few grains of flaky salt on the tops.
Bake the cookies until just set on the edges, and puffed and wet in the centers, 10 - 12 minutes, rotating front to back and top to bottom halfway through. The cookies will look underdone, but will continue to cook as they cool. (If you accidentally over bake, remove the cookies from the pans and onto cooling racks immediately.) Cool the cookies completely on the pans. Store in an airtight container at room temperature for up to a few days.
Feel free to double the recipe, as this makes a fairly small batch of cookies, as far as batches of cookies go.If you don't want to eat them all at once, scoop the remaining dough into balls and store in an airtight container in the fridge (the dough is hard to scoop when cold).Cookies baked from chilled dough don't spread as much, yielding a thicker cookie.Jay says these are his faves.Nutritional values are based on one of twenty four cookies.