Put the butter in the skillet, and place in the oven for a few minutes or until butter is completely melted.
Blend the eggs, flour, milk, sugar, vanilla, and salt in a stand mixer or blender.
Remove the skillet from the oven and allow the butter to coat the entire bottom and sides of the skillet. Pour any remaining butter into the batter and mix again.
Pour the batter into the hot skillet, and place about half of the peach slices in the batter (save the rest for topping). Bake for 20-25 minutes or until puffed and golden brown.
Arrange the remaining peach slices on top, and add additional toppings like sliced almonds and powdered sugar if desired.