From the wonderful blog https://smittenkitchen.com/2015/04/salted-chocolate-chunk-cookies/. You must read her blog as she is very convincing and funny about needing another chocolate chip cookie recipe! This is a winner and delicious!
1/2 cup (4 ounces or 113 grams) unsalted butter, at room temperature
2 tablespoons (25 grams) granulated sugar
2 tablespoons (25 grams) turbinado sugar (aka Sugar in the Raw; you can use more brown or white if you don’t have this, but the subtle crunch it adds is delightful)
3/4 cup plus 2 tablespoons (165 grams) packed light or dark brown sugar
1 large egg
1 teaspoon vanilla extract
3/4 teaspoon baking soda
Heaped 1/4 teaspoon (or, technically, 1/4 + 1/8 teaspoon) fine sea or table salt
1 3/4 cups (220 grams) all-purpose flour
1/2 pound (225 grams) semi- or bittersweet chocolate, cut into roughly 1/2-inch chunks with a serrated knife
Flaky sea salt, to finish
Heat oven to 360°F (180°C) and line a baking sheet with parchment paper or a silicon baking mat.
In a large bowl, cream the butter and sugars together with an electric mixer until very light and fluffy, about 5 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. The dough will look crumbly at this point. With a spatula, fold/stir in the chocolate chunks.
Scoop cookies into 1 1/2 tablespoon (I used a #40 scoop) mounds, spacing them apart on the prepared baking sheet. Sprinkle each with a few flakes of sea salt. Bake for 11 to 12 minutes, until golden on the outside but still very gooey and soft inside. Out of the oven, let rest on baking sheet out of the for 5 minutes before transferring a cooling rack.