In a large bowl or stand mixer, combine flour, cornmeal, salt, sugar, and yeast. Mix briefly.
Add warm water (about 90°F) and ¼ cup melted butter. Mix on low speed or by hand until dough comes together and becomes soft and pulls away from the bowl, about 4-5 minutes. Add 1 tsp water if too stiff or 1 Tbsp flour if too sticky.
Form dough into a ball. Place in an oiled bowl, turning to coat. Cover with foil and let rise in a warm spot for 1-2 hours until doubled.
Punch down dough and roll into a 15x12-inch rectangle on a floured surface. Spread ¼ cup softened butter over the dough. Roll up lengthwise and cut in half. Form each piece into a ball, return to greased bowl, cover, and refrigerate for 1 hour.