Preheat the oven to 350°F. Lightly grease a 12 inch cast iron skillet and set aside.
In a large bowl, cream together the butter and sugar until light and fluffy. Add in the eggs one at a time, and mix in until fully incorporated.
In a separate bowl, mix together the flour, cream of tartar, baking soda and salt.
Slowly add the dry ingredients to the wet ingredients, mixing until fully combined. Pour the batter into the prepared skillet.
In a small bowl, mix together the topping ingredients. Sprinkle evenly over the cookie dough.
Place the skillet in the preheated oven for 35 minutes. Remove from oven and allow to cool. Top with ice cream. (optional, but highly recommended)