Step 1

Place a 10-inch cast iron skillet on the middle rack in the oven. Heat the oven to 425°F.

Step 2

Make the strawberry filling: Place 1/3 cup granulated sugar in a medium bowl. Finely grate the zest of 1 medium lemon onto the sugar. Rub the zest into the sugar with your fingertips until fully combined and gritty. Hull and cut 1 pound strawberries in half, then place in a large bowl. Squeeze the juice of the zested lemon onto the strawberries and toss to combine.

Step 3

Cut 5 tablespoons unsalted butter into 5 pieces. Place the butter in the hot skillet, return to the oven, and bake until the butter is mostly melted but not browned, 1 to 2 minutes. Add most of the lemon sugar and stir to combine. Arrange the strawberries evenly on top and sprinkle with the remaining lemon sugar. (Reserve both bowls.) Roast for 10 minutes. Meanwhile, make the Dutch baby batter.

Step 4

Make the batter: Wipe out the lemon sugar bowl. Place 3/4 cup all-purpose flour, 2 tablespoons granulated sugar, 1/2 teaspoon kosher salt, and 1/2 teaspoon ground cardamom in the bowl and whisk to combine.

Step 5

Wipe out the strawberry bowl. Add 5 large eggs to the bowl and whisk until frothy. Add 1 cup whole milk and 1 teaspoon vanilla extract and whisk to combine. While whisking constantly, slowly add the flour mixture and whisk until smooth. Whisk vigorously for 30 seconds more. (Alternatively, just whiz everything together in a blender until smooth.)

Step 6

By this point the strawberries should be bubbling and smell roasted and sweet. Pour the batter over the strawberries. Reduce the oven temperature to 400°F. Bake until puffed and golden-brown, about 20 minutes. Let cool for 5 minutes. Serve dusted with powdered sugar and topped with whipped cream if desired.