Prep the squash: Wash the yellow squash thoroughly. Cut off the ends and slice each one into thin rounds or half-moons (about 1/4-inch thick). This ensures even cooking.

Boil the squash: Place the sliced squash in a large pot and cover with water. Add a pinch of salt if desired (though Brenda often skips it). Bring to a boil over medium-high heat, then reduce to a simmer. Cook for 10-15 minutes until the squash is fork-tender but not mushy. Drain well in a colander – press gently to remove excess water and prevent a soggy casserole.

Sauté the veggies: While the squash drains, melt half a stick (1/4 cup) of salted butter in a large skillet over medium heat. Add the chopped onion and bell pepper. Sauté for 5-7 minutes until softened and fragrant, stirring occasionally. Remove from heat.

Mix the filling: In a large mixing bowl, whisk together the mayonnaise, beaten eggs, and black pepper to taste. Stir in the cubed processed cheese. Add the drained squash and the sautéed onion-bell pepper mixture (including any butter from the pan). Gently fold everything together until well combined. The heat from the squash will start melting the cheese slightly.

Prepare the topping: In a separate bowl, crush the sleeve of round crackers into fine crumbs (use your hands or a rolling pin in a zip-top bag). Melt the remaining half stick (1/4 cup) of butter and pour it over the crumbs. Stir until evenly coated for that perfect crunchy top.

Assemble and bake: Preheat your oven to 350°F (175°C). Grease a 9x13-inch casserole dish lightly (or use nonstick spray). Pour the squash mixture into the dish and spread evenly. Sprinkle the buttered cracker crumbs over the top, covering every corner for even distribution.

Bake to perfection: Place in the preheated oven and bake for 30-40 minutes. Check at 30 minutes – the top should be golden brown and the edges bubbly. If needed, broil for 1-2 minutes for extra crispiness (watch closely to avoid burning).

Rest and serve: Remove from the oven and let it sit for 5-10 minutes. This allows the flavors to meld and makes serving easier.