Whisk together 2 1/2 cups flour, yeast, sugar, and salt in the bowl of a stand mixer.

Heat buttermilk, water, and oil in a small saucepan until warm (120° to 130°F). Add to flour mixture.

Using the flat beater, mix on low speed until moistened. Increase speed to medium and mix for 3 minutes.

Change flat beater to dough hook. Turn mixer on low (setting 1 or 2 or as recommended by manufacturer when using dough hook). Gradually add parmesan and enough remaining flour to make a firm dough. Knead for 4 to 5 minutes.

Turn dough out on a lightly floured surface. Knead a few times and shape into a ball. Place the dough in the greased bowl and turn to coat dough. Cover and let rise in a warm draft-free place until double, about 1 hour.

Lightly grease two 9- X 5-inch loaf pans while dough is rising.

Punch down dough and divide in half. On a lightly floured surface, roll one half to a 16- X 10-inch rectangle. Brush with half of melted butter.

Cut into four 10- X 4-inch rectangles. Stack dough pieces, butter side up. Cut into 5 stacks, 4- X 2-inches.

Place stacks in a row in the pan cut side down. Repeat with remaining dough half.

Cover loaves and let rise in a warm, draft-free place until almost double, about 30 minutes.

Preheat oven to 375°F while the loaves are rising.

Bake loaves for 30 minutes or until golden brown.

Transfer loaves from pans to wire racks. Cool completely.