Set the oven to 350°F and allow it to preheat. A fully heated oven helps the provolone soften evenly across the baking sheet.

Cover your baking sheet or sheets with parchment and distribute all 24 provolone slices with gaps between them. Each slice needs room to spread without joining its neighbor.

Combine the cooked, drained sausage with the cream cheese, sour cream, and shredded mozzarella in a small bowl. The finished filling should look evenly mixed and hold together when scooped.

Bake each tray for about 3 minutes, then remove it when bubbles appear and the rims begin turning golden; leave it to rest for 3 to 5 minutes. Work through multiple trays in stages so the cheese stays flexible enough to lift without running or cracking.

Divide scoops of filling among the centers of 12 wrappers, then use a spatula to lift the other 12 wrappers over them. Leave a clear border around each mound so the cheese layers can meet.

Press the upper and lower cheese layers together around each parcel’s perimeter. The warm edges should yield under gentle pressure without forcing filling into the seam.

Switch to broil and return the tray for approximately 30 seconds, watching continuously. Remove the tray as soon as the upper cheese softens enough to fuse the edges, before the wrappers scorch.

Lift the tray out and let the ravioli settle for a few minutes before transferring them to plates. The parcels should firm enough to move while keeping their tender, melted centers.