Preheat oven to 375 degrees. Put all of the butter in the bottom of a cast iron skillet and place it in the oven until completely melted.
In a bowl, add together eggs and beat with a hand-mixer until fluffy.
Add in milk, flour, stevia, salt, and vanilla and mix until the mixture resembles thick cream.
Take the skillet with melted butter out of the oven and pour in egg mixture.
Bake for 20-25 minutes or until a toothpick comes out clean. It should be light brown and a bit crispy around the edges when done. It will rise above the edges of the skillet and look like it is inflated.
It will fall once removed from oven. Take skillet out and flip onto a plate. (this is my addition.)
Slice and serve immediately and warm with powdered sugar, berries or other delicious addition!