1. Preheat the oven to 400°. Generously coat a 10-inch cast iron skillet with the butter.
2. Process the eggs and next 5 ingredients in a blender until well blended. Add the flour and process until smooth and well blended.
3. Scatter the cherries in the prepared skillet and pour the batter over them. Bake until puffed and golden, about 30 minutes. Lightly dust with confectioners' sugar before serving, if desired.