Preheat oven to 450°F. In medium bowl, toss apple slices with brown sugar. Arrange apple slices in even layer in the bottom of 12" cast iron skillet. Pour 4 tablespoon melted butter over apples. Place skillet in the oven for 10 minutes.
While skillet is heating up, add remaining 2 tablespoon melted butter, eggs, milk, flour, vanilla extract, cinnamon, salt and nutmeg to blender and blend on high for 1 minute or until batter is smooth. Remove skillet from oven and pour batter in.
Bake for 18-20 minutes and then reduce temperature to 300°F and bake for another 5 minutes. DO NOT open oven during the first 15 minutes or the pancake might deflate. Remove when pancake is puffed and brown on top. Drizzle some caramel over it and top with whipped cream.
Salted Bourbon Caramel
While dutch baby is baking, make the caramel. In a dry, deep skillet cook the sugar over medium-high heat. Stir constantly with rubber spatula until the sugar is melted and turns a golden caramel color. Remove from heat and add the chunks of butter, one at a time. Whisk until combined. The caramel will bubble from this, but that is expected.
Slowly add the cream and whisky until everything is combined. Return the skillet to medium heat and cook, stirring constantly for 3-5 minutes or until caramel thickens. Remove from heat and add bourbon and salt. Set aside to cool.
Whipped Ricotta Cream
In bowl of stand mixer with whisk attachment, whip the cream, sugar and vanilla extract on medium-high until medium peaks form, about 3-4 minutes.
Room Temperature Ingredients: If time permits, make sure the butter, eggs and milk are room temperature.
Mix Well: It’s important to make sure all of the ingredients are mixed well, which is why a blender works great. But you can go old school and just use a wooden spoon to mix everything.
Preheat the Skillet: It’s important to preheat the skillet so it’s ready as soon as the batter hits the pan. This contributes to the browning on the bottom of the pancake and its rise. If you have time, let the skillet sit in a heated up oven for at least 30 minutes before adding butter, then the batter.
Use Cast Iron:Cast iron skillets are meant for dutch babies. If you don’t have a cast iron skillet, make sure you are using a pan that can go in the oven.
Make Batter Ahead of Time: If you want a really tall pancake, make the batter ahead of time and place in airtight container in the fridge overnight. You can actually keep batter in fridge for up to 3 days before using it.