You’ll love this easy, cheesy spinach squares recipe! This classic appetizer is a must save for effortless entertaining. You can even bake ahead and freeze!
I love looking through old recipe books. You know, the kind where half the ingredients aren’t even made anymore. The measurements are approximate. A few of the steps are completely missing.
It’s like the authors assume everyone knows the recipe and just needs a quick reference guide so they don’t miss an ingredient.
These spinach squares are exactly the kind of recipe you’ll find in those books. Only the ingredients are simple enough that they’re never going out of style. This recipe shouldn’t either. I’m a bit sad I hadn’t really tested it before this year!
Spinach Squares Ingredient Notes
Can I just say that these are a fabulous budget-friendly appetizer recipe? The main ingredients are easy to find, inexpensive, and flexible!
The first ingredient you’ll need is… spinach. Buuuuuttttt, for simplicity, you want frozen spinach. If you use fresh, you’ll have to cook it down, let it cool, and chop it so you don’t have spinach strings.
Busy cook that you are, there’s no time for that! Buy chopped frozen spinach, thaw it. Squeeze out the excess liquid and move along! These squares will take less than 10 minutes from start to oven using this shortcut.
Also, the onion is optional. But you won’t really taste it and it does add a really nice flavor. I prefer to use either red or sweet onion, but use what you have.
And if you’d really like to amp up the savory flavors, feel free to add a little garlic. Or make the squares a bit spicy with some red pepper flakes.
Let’s talk about cheese
Consider the type of cheese in the recipe as a suggestion. Honestly, whatever cheese you like with spinach is GREAT!
I have also used this recipe to use up those assorted bags of shredded cheese in the fridge that only have about 1/3 cup left in each. No one seems to want to finish them, so this is a good way to do it.
Side note, is that just my family? I love them, and normally they are great about not leaving little bits in containers in the fridge. But when it comes to shredded cheese, no one touches the bag when it’s at less than the last half cup. So weird to me.
Anyway, I would recommend half the cheese be of a stringy melty variety. I’ve found that if you do that, the squares reheat to “fresh from the oven” quality. If you use strictly a less “melty” cheese like cheddar, they will lose a little in the reheat.
Which brings me to….
Why spinach squares are the make-ahead appetizer you need…
Darlings… these are perfect to make in advance! Seriously, you can make them up to 3 days ahead of serving and refrigerate, or freeze them for up to a month!
The recipe makes about 2 dozen depending on how you cut them. So you can always make the full batch and split a portion depending on what you need.
For example, while we do bigger holiday meals for Thanksgiving and Christmas, New Year’s Eve is always heavy appetizers. So while I might make a batch of these squares to serve as a starter with the Christmas meal, I’ll freeze a portion to reheat for New Year’s Eve.
A few more notes…
If you’re serving these as part of a couple starters, cut them on the smaller side. These spinach cheese squares are FILLING!
They smelled amazing, so the Godfather and I ate two of the bigger squares each after I finished shooting. This was just before lunch. We didn’t finish our lunch.
Extras are also reeeeallly good warmed and topped with a runny egg for breakfast. It’s like a lazy-cook’s florentine eggs and so good!
I hope you enjoy this recipe darlings!
- 3 tablespoons unsalted butter
- 3 large eggs
- 1 cup all-purpose flour
- 1 cup milk
- 1 teaspoon kosher salt
- 1 teaspoon baking powder
- 1/4 cup finely diced onion (optional)
- 1 pound shredded cheese (see notes)
- 2 10-ounce packages of frozen chopped spinach, thawed and drained
- Preheat your oven to 350 F. Melt the butter in a 9x13-inch casserole dish while the oven heats and you mix your batter.
- Once the butter has melted, remove the pan. You may need to use a pastry brush to ensure the butter is evenly spread over the dish.
- While the oven is preheating, whisk together the eggs in a large mixing bowl. Add the flour, milk, salt, and baking powder. Stir to combine.
- Add the onion, cheese, and thawed spinach to the bowl. Stir to combine, then pour into your prepared casserole dish.
- Bake for 30-35 minutes until golden brown on top. Remove and allow to cool 30-40 minutes to set. At this time, bars can either be cut, or refrigerated up to 3 days, reheat before serving (see step 8).
- Cut into squares and serve warm or at room temperature.
- If preparing in advance to freeze: Cool the squares, cut, and freeze the spinach squares in a single layer on a baking sheet until solid. Then place in an airtight container. When you wish to serve, place the desired number of squares on a baking sheet and bake in a 325 F oven for 8-12 minutes until warmed through.
- To reheat refrigerated squares, bake in a 325 F oven for 5-10 minutes until just warmed through. You can also microwave for a few seconds, but the texture is better when warmed in the oven - almost identical to fresh!
- In this recipe, I used a half-pound of shredded cheddar and a half-pound of shredded Monterey Jack cheese. Use any combination of cheese that you like with spinach. An Italian shredded cheese blend with a sprinkle of Parmesan on top just before baking is another family favorite.
- You can omit the onion if you really hate it, but we like the texture it adds to the bars. Measurement doesn't have to be precise, but I wouldn't go with more than half of a small/medium-small onion.
- This recipe will work with non-dairy butter, milk, and cheese.
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