1 1/2 cups all-purpose flour
1/3 cup granulated sugar
2 1/4 teaspoons baking powder
1 teaspoon ground cinnamon
1/4 teaspoon kosher salt
1 large egg — beaten
1/2 cup milk
3 tablespoons unsalted butter — melted
Garnish: Powdered sugar
Pour oil to depth of 1 1/2 inches into a 12-inch cast-iron skillet; heat to 350°.
Whisk together flour and next 4 ingredients in a large bowl. Make a well in center of mixture; stir in egg and next 2 ingredients until well blended. (Batter will be dry).
Drop batter by level tablespoonfuls, 6 to 8 at a time, into hot oil; fry, in batches, turning occasionally, 2 minutes on each side or until browned.
Drain on a paper towel-lined plate. Serve warm.