I made this for a church potluck and got great reviews! I didn't follow the recipe exactly (do I ever?), so here is what I did differently:

I used a 13 x 9 dish instead of a 3-qt. casserole.

I used frozen squash. Because it was more watery, I reduced the mayonnaise to 3/4 cup. (I am looking forward to making it with fresh squash!)

For the buttered bread crumbs, I whirred four slices of plain white bread in the food processor and tossed the resulting crumbs with 1/2 stick of melted butter. This was the perfect amount to top a 13 x 9 pan, but might be too much if you use a casserole dish.