Preheat the oven to 425°F.
Place a 10-inch cast iron skillet in the middle of the oven for 15 minutes to preheat.
Meanwhile, add all the batter ingredients to a bender and blend until smooth, about 20 seconds.
When the skillet is hot, remove from the oven using a glove and add the butter. Place back in the oven for 1 minute. Once the butter is melted and sizzling, pour the batter into the skillet and place back in the center of the oven for 12 - 15 minutes or until cooked through and golden on top to your liking. Try not to open the oven before at least 12 minutes. Opening the oven too many times will make it denser.
Brush with a little more butter. Cut the Keto Dutch Baby into 6 slices and serve with your favorite optional toppings. Today's recipe is served with optional toppings that include whipped cream, stewed raspberries, fresh blueberries and dusted with a little powdered sweetener.
Storage: Fridge for up to 3 days