Preheat oven to 425°F (220°C). Place a 10- to 12-inch ovenproof skillet (preferably cast iron) on the middle rack while the oven heats so the pan becomes very hot.

Blend batter

In a blender (or using a whisk and a large bowl), combine 4 large eggs, 1 cup whole milk, 3 tablespoons all-purpose flour, 2 teaspoons granulated sugar, 1 teaspoon ground cardamom, 1/4 teaspoon fine sea salt, and 1 teaspoon vanilla extract. Blend or whisk until completely smooth and slightly frothy, about 20–30 seconds in a blender or 1–2 minutes by hand. Let the batter rest while the pan heats (5 minutes).

For the pan & finishing

Heat the butter

Once the oven (and skillet) are hot — about 5–7 minutes after reaching temperature — carefully remove the skillet using oven mitts. Add 3 tablespoons unsalted butter to the hot pan and swirl until the butter is fully melted and begins to foam and just turn a light golden brown (watch closely to prevent burning), about 30–45 seconds.

Bake the Dutch baby

Immediately pour the prepared batter into the sizzling butter in the hot skillet (it will start to puff up at the edges). Return the skillet to the oven and bake undisturbed for 18–22 minutes, until the edges are deeply puffed, set, and golden brown and the center is set but still slightly custardy.

Finish and serve

Remove the skillet from the oven. Sprinkle 2 tablespoons confectioners' sugar over the pancake and squeeze the juice of half a fresh lemon evenly across the top. Top with 1 cup fresh berries or sliced fruit if using, and serve immediately with maple syrup on the side. The pancake will deflate slightly as it cools — slice into 4 portions and transfer to plates.