Place chilled butter between parchment; pound to 6-inch square. Chill until firm.
STEP 2
Roll bread dough into a 12 x 8-inch rectangle. Place butter on one side, sprinkle with sugar. Fold over and seal. Roll into a 20 x 8-inch rectangle, folding edges into the center. Chill.
STEP 3
Roll dough again and sprinkle with sugar. Repeat folding and chilling a total of three times.
STEP 4
Butter a 9-inch cast-iron skillet. Roll dough into a rough 9-inch circle and let rise for 45 minutes.
STEP 5
Preheat oven to 425°F. Make 6 cuts in dough, brush with melted butter and sprinkle with sugar. Bake for 40-44 minutes. Cool for 30 minutes before serving.