Our Most Popular Breakfast Casserole Is the Perfect Make-Ahead Recipe

The comfort and versatility of a casserole can’t be beat. No matter for dinner or brunch, as a sidekick or star of the show, there’s almost always a casserole that fits the bill. It probably comes as no surprise that we here at Simply Recipes love a good casserole. We love them so much, in fact, that we’ve given a fair share of recipes the casserole treatment—from viral meals like Marry Me Chicken to classic dishes such as Everything Bagel breakfast sandwiches.  

This Spinach Florentine Casserole is another example of how traditional flavors can be married with the ease and coziness of a casserole. Combining the elegance of French Florentine-style cooking with the comfort of a baked dish, this recipe strikes a perfect balance: It’s interesting enough for special occasions like Christmas morning, but also simple enough to whip up for those breakfast-for-dinner nights.

With its versatility and ease of preparation, it’s no wonder nearly half a million readers have fallen in love with this recipe, making it Simply Recipes’ top casserole of all time. Give it a try and you’ll understand the hype with the very first bite.

Why You’ll Love This Spinach Florentine Casserole

Featuring a creamy spinach-studded filling and English muffin topping, this casserole may seem unassuming at first glance. But, as Marla E. notes in the recipe’s comments, “it came out beyond my expectations.” The spinach, eggs, and combination of Parmesan and mascarpone cheeses come together to create a dish that’s indulgent and satisfying. The straightforward assembly keeps it approachable for home cooks of all levels. It’s a dish that feels special without requiring hours in the kitchen.

Tips for Making Spinach Florentine Casserole

This recipe is simple, but a few tips can make the prep even easier.

1. Don’t forget to thaw and drain the spinach. The recipe calls for frozen spinach, so there’s no need to rush out to the grocery store for fresh greens. Just be sure to thaw the frozen spinach and squeeze out as much liquid as possible before using.
2. Grate your own cheese. Pre-shredded cheese contains anti-caking agents that can affect the texture of the sauce. It requires a bit more work, but grating fresh cheese ensures a creamier, more velvety texture.
3. Allow the casserole to rest. Let the assembled dish sit in the fridge for at least an hour so the flavors can meld and the English muffins can absorb some of the liquid.
4. Prep it in advance. Assemble the casserole the night before and refrigerate it for up to 12 hours overnight, then bake fresh when ready. This makes it perfect for hosting or busy mornings.
5. Customize it to your tastes. Add crumbled sausage, crispy bacon bits, or sun-dried tomatoes for extra flavor.