Melt butter in cast iron skilled over medium-low heat. Remove from heat.

In medium bowl, whisk eggs, them combine with milk and vanilla extract.

In a large bowl, combine dry ingredients.

Carefully pour 2/3 of egg mixture into dry ingredients and whisk to combine. Add the remaining egg mixture and whisk until lumps are gone.

Pour mixture in cast iron skillet over the butter and place in a cold oven.

Turn the oven on to 375 degrees and bake 30-40 minutes, or until the pancake is very poofy and golden brown.

Remove from oven, cut into slices, and serve with toppings of choice.