Step 1

Preheat oven to 450ºF (convection roast if you have it). Line two baking sheets — I love these extra-large baking sheets for this — with parchment (for easy cleanup). In a very large bowl (or two large bowls if you don’t have an extra-large one), dress the squash with 1/4 cup olive oil and salt to taste — be generous. Season with pepper to taste as well. Toss well — the slices should feel evenly oiled.

Step 2

Transfer the seasoned squash to each of the prepared sheet pans and spread in an even layer — it’s OK if some of the squash are overlapping. Transfer the pans to the oven, and bake until the slices are beginning to brown, 15 to 20 minutes. Rotate the pans. Bake for 10 to 15 more minutes or until most of the slices are golden — it’s very likely that one of the squash will look completely done and some will look like they need more time. This is fine — the goal with the roasting is mostly to remove moisture so that the finished casserole is not watery. Remove pans from the oven and set aside. Reduce oven temperature to 400 degrees.

Step 3

Meanwhile, toss the 2 cups bread crumbs with 1/3 cup of the grated parmesan cheese, 1/4 cup olive oil, and salt and pepper to taste. Set aside.

Step 4

Into a 9×13-inch baking dish, spoon a small amount of sauce (about 1/2 cup), then a single layer of roasted squash, then a thin layer of parmesan. Repeat the layering until all of the squash and cheese has been used, ending with a little sauce. Top with the bread crumb mixture.

Step 5

Bake until the squash mixture is bubbly and the top is golden, 25 minutes or so depending on size of pan and thickness of layers. Remove from heat and allow to rest for 5 minutes before serving. This can also be made ahead and reheated.