01 -
Place an oven rack in the middle position and preheat the oven to 450°F. Place a 9- or 10-inch cast iron skillet over low heat on your stovetop and keep it over low heat while you prepare the batter.
02 -
Melt two tablespoons of butter in a small skillet, then transfer to a blender. Add the milk, flour, eggs, granulated sugar, vanilla, salt, and lemon zest, and blend until smooth. Do not skip this step to avoid lumps.
03 -
Place the remaining 2 tablespoons of butter into the cast iron skillet and turn the heat up to medium-high. Let the butter melt, then add the blueberries and give the skillet a shake.
04 -
Immediately pour the batter over the blueberries and transfer the skillet to the oven. Bake until the pancake is puffed and golden, approximately 15 minutes.
05 -
Remove the pan from the oven, dust with confectioners’ sugar if desired, cut into portions, and serve immediately with maple syrup.