Preheat the oven to 350° and generously grease the bottom and sides of a 5-inch cast-iron skillet with coconut oil.

In a large bowl, whisk together the flour, baking soda, and salt. Set aside.

In a large mixing bowl, beat coconut oil, sugar, and brown sugar on medium speed for 2 minutes. Add the egg and vanilla, beating until well combined.

Add the dry ingredients to the wet ingredients, mix on low speed just until combine. Mix in the coconut and chocolate chips on low speed.

Divide the dough in half. (Freeze half the dough for another day or use two mini skillets.) Press half the cookie dough into the prepared skillet and bake for 18 to 20 minutes, until the edges are crisp and the cookie is golden and cooked through. Remove from oven. If desired, serve warm topped with vanilla ice cream and hot fudge.