Preheat oven to 350 degrees Fahrenheit.
In a bowl, mix 6 tablespoons of room temperature butter with 3/4 cup plus 1 Tablespoon of brown sugar. Rapidly stir in one egg, plus one teaspoon of vanilla.
Add 1 Cup of Einkorn flour, 1/'2 tsp baking soda, and 1/2 tsp coarse salt. Stir until the dough is smooth.
Mix in 3/4 cup dark chocolate chips.
Grease a 8-10 inch cast iron skillet with butter or coconut oil.
Spread the dough evenly in the cast iron skillet. Sprinkle remaining salt over the top.
Bake 18-20 minutes.