Lightly cream butter and sugar. Try not to incorporate too much air.
Add eggs one at a time, mixing after each until smooth.
Add vanilla and kosher salt.
Add flour and chocolates, mixing just until combined. Feves are larger chocolate disks that make for great layers of chocolate in the cookies, they also tend to be made with higher quality chocolate.
Refrigerate cookie dough for a half hour before portioning. Use a 1 oz cookie scoop or aim for balls that are about 2 Tbsp in size. Sprinkle with a little Maldon.
Bake at 350 degrees for 7-8 minutes, depending on your oven. The cookies will turn golden brown at the edges. They should still be slightly puffy in the middle, but starting to color in the middle as well.