First Step: Preheat Oven and Skillet
Preheat your oven to 450°F (230°C) and place the oven rack in the center position. Heat a 9- to 12-inch cast iron skillet or ovenproof pan on low heat on the stovetop while you prepare the batter. Proper heat ensures even cooking and puffiness.

Second Step: Prepare the Batter
Melt 2 tablespoons of butter in a small skillet or microwave until fully melted. Transfer the melted butter to a blender or mixing bowl. Add 4 large eggs, ½ cup milk, ½ cup all-purpose flour (or alternate flour), 3 tablespoons sugar (if using), 1 teaspoon vanilla extract, ¼ teaspoon salt, and the zest of one lemon. Blend or whisk vigorously until the batter is smooth with no lumps, as this helps the pancake rise evenly and creates the signature custardy texture.

Third Step: Prepare the Skillet and Add Blueberries
Carefully place the remaining 2 tablespoons of butter into the hot cast iron skillet. Increase stovetop heat to medium-high and allow the butter to melt and brown slightly for nutty flavor. Add 1 cup of fresh or frozen blueberries to the skillet and gently toss to coat them evenly in the butter.

Fourth Step: Bake the Dutch Baby Pancake
Immediately pour the prepared batter over the blueberries in the skillet, then transfer the skillet to the preheated oven. Bake for approximately 15 minutes, or until the pancake puffs dramatically and turns a golden brown color. Avoid opening the oven door during baking to prevent the pancake from collapsing prematurely.

Final Step: Serve and Garnish
Remove the Dutch baby pancake from the oven and let it settle for a minute. Dust with confectioners’ sugar if desired and serve immediately with maple syrup on the side. The pancake is best enjoyed warm, as it starts to deflate after coming out of the oven.