Butter 10 rings 2½ in/6 cm in diameter and 1½ in/4 cm high, or spray lightly with cooking spray, and place on a sheet pan lined with parchment paper. Scale the brioche dough into 10 pieces, 2 oz/60 g each, and roll into balls. Place each ball into a ring and proof at 80° to 85°F/27° to 29°C until doubled in size, 1½ to 2 hours.