Prep time: 20 minutes
Total time: 3 1/2 hours, plus overnight fermentation
for the dough:
3 ½ cups|450 grams '00' flour, plus more for dusting
½ cup|50 grams whole wheat flour
1 tablespoon|12 grams kosher salt
1 teaspoon|3 grams active dry yeast
for the filling:
1 pound|453 grams sliced mortadella
1 pound|453 grams fresh ricotta
1 cup|130 grams grated parmesan cheese
1. Make the dough: Mix the dry ingredients in a bowl with a wooden spoon. Add 400 grams water heated to 115°F and stir with the spoon until a shaggy dough forms. Cover and sit at room temperature for 1 hour, then refrigerate overnight.
2. The next day, on a lightly floured surface, form the relatively wet dough into a ball. Place back in the bowl and cover with plastic wrap. Place in a warm place until doubled in size, about 1 hour more.
3. On a lightly floured surface, stretch the dough into a rectangle. Lay the mortadella over the dough leaving 2-inches of dough exposed. Spread the ricotta on the mortadella. Sprinkle with the parmesan and roll into a long log like a jelly roll. Cut the dough into 2-inch "buns" and place on a lightly oiled sheet tray. Cover and proof for 1 hour in a warm spot.
4. Heat the oven to 450°F. Bake the buns for 12 to 15 minutes, or until golden brown.