This easy squash casserole combines tender yellow squash in a super creamy, cheesy sauce, all topped off with a buttery cracker topping for a crowd-pleasing summer side dish for potlucks, picnics, holidays, and cookouts!
Rinse and slice the squash into 1/3-14-inch rounds and dice the onion.Preheat the oven to 350°F/175ºC and grease a 9.5×6.5 inch casserole/baking dish.
Par-cook the squash
Heat the oil in a large skillet over medium-high heat until the oil shimmers. Then add the onion and sauté for two minutes.
Add the summer squash pieces and cook, loosely covered, for 10 minutes, until the center of the squash becomes tender.If you don’t have one large enough, you may have to do this in two batches or two separate pans.
Add the thyme, salt, and pepper, stir, and cook for 2-3 minutes uncovered for some of the liquid to evaporate.
If there's still a LOT of liquid in the pan and you prefer a drier casserole, drain the mixture through a colander for 5 minutes.
Prepare the cream sauce
In a large bowl, combine the eggs, cream cheese, sour cream, and between ½-⅔ of the shredded cheese and whisk/mix until thoroughly combined.
Make the topping
Melt the butter on the stovetop or in the microwave (for 20-30 seconds).
Crush the crackers into a crumb consistency by placing them in a Ziplock and bashing them with a rolling pin or the bottom of a heavy glass.
In a bowl, add the melted butter and the crushed cracker crumbs and mix thoroughly.
Assemble and bake
Spread the par-cooked squash mixture into the prepared baking/casserole dish, then pour over the cream mixture and mix well.
Sprinkle over the remaining shredded cheese and cracker mixture, spreading it evenly over the top.
Transfer the dish to the oven and bake until it's golden brown on top with a bubbly filling – this should take about 20 minutes at 350°F/175ºC.Optionally broil it for a minute or two at the end if it hasn’t browned enough.
Leave it to sit for just a few minutes (3-5) before serving to allow it to thicken up slightly.
Video
Notes
For a 9x13 pan: Double all the ingredients. This makes for a great large family portion.
Do you peel yellow squash before cooking? There’s no need, as the peel is thin and tender (even more so once cooked).
To skip the par-cooking: Slice the squash ¼-inch thick and add 10-15 minutes to the baking time. However, unless you pre-salt the squash, this version will be wetter.
Make a zucchini casserole: Or use a combination of yellow squash and zucchini. The method remains the same.
Squash Casserole Add-ins
Add extra seasonings like garlic powder (or fresh garlic), smoked or sweet paprika, chili powder/cayenne pepper, red pepper flakes, etc.
Other topping options include crushed cornflakes, potato chips, seasoned breadcrumbs/panko breadcrumbs, dry stuffing mix (with butter), etc.
Experiment with cheese depending on your desired flavor (sharp, mellow, spicy, etc.)
Add more fresh herbs to garnish. I.e., parsley, chives, basil, green onion, etc.
Bulk it with extra vegetables: corn, peas, chopped bell pepper (sauteed), etc.
Make it more of a main with shredded chicken, crumbled or sliced bacon, or sausage.