1-First step: Preheat and prep the baking dish Start by preheating your oven to 350 degrees Fahrenheit. While the oven heats, prepare a 3-quart baking dish with cooking spray. This helps the casserole release cleanly after baking and keeps cleanup simple. Having the dish ready before you start mixing saves time and keeps the process smooth.

2-Second step: Mix the pineapple base In a large bowl, add the drained pineapple chunks, the reserved 2 tablespoons pineapple juice, sugar, and flour. Stir everything together until the flour disappears and the pineapple looks evenly coated. The reserved juice helps the mixture come together without making it too dry, while the flour thickens the filling as it bakes. Take a moment here to break up any clumps of sugar or flour. A smooth mixture now helps the casserole bake more evenly later.

3-Third step: Add the cheese Next, stir in the shredded cheddar cheese. Mix until the cheese is well distributed through the pineapple filling. This is the part that makes pineapple casserole so unique. The savory cheese plays off the sweetness of the fruit in a way that feels comforting and a little old-fashioned. Do not worry if the mixture looks unusual before baking. That sweet-savory combo is exactly what makes this dish such a favorite.

4-Fourth step: Transfer to the baking dish Spoon the pineapple mixture into the prepared casserole dish and spread it out in an even layer. Try not to pack it down too tightly. A light, even layer helps the filling heat through and gives the topping a good surface to crisp up. If you are making this for a holiday meal, this is a good stopping point for a make-ahead plan. You can cover the dish and chill it before adding the cracker topping later.

5-Fifth step: Make the crumb topping In a separate bowl, combine the crushed crackers, melted butter, cinnamon, and nutmeg. Stir until the crumbs are evenly coated. The topping should look moist and sandy, not soggy. Butter helps the topping brown beautifully and gives it that rich, classic flavor. If you like a little more texture, crush the crackers by hand instead of grinding them too fine. A mix of small crumbs and slightly larger bits gives the top more crunch.

6-Sixth step: Add the topping Sprinkle the cracker mixture evenly over the pineapple filling. Cover the surface from edge to edge so every serving gets some crunchy topping. This step gives the casserole its signature finish and helps keep the sweet filling tucked underneath a crisp, buttery layer.

7-Seventh step: Bake until bubbly Bake the casserole for 25 to 30 minutes, or until the top is golden brown and the filling is bubbling around the edges. That bubbling is a great sign that the filling has thickened and everything is heating through. If the top browns too quickly, you can loosely cover it with foil during the last few minutes. The aroma at this point is wonderful. You will get sweet pineapple, warm spice, and buttery cracker notes all at once.

8-Final step: Rest and serve Remove the casserole from the oven and let it rest at room temperature for 5 minutes before serving. This short rest helps the filling settle a little so it is easier to scoop. Serve it warm alongside your favorite main dish. If you are building a holiday spread, this dish pairs nicely with ham and other comforting recipes like a cozy apple crisp dessert for a sweet finish.