1(9 ounce) package frozen chopped spinach, cooked and squeezed dry
Mix all ingredients together. Place mixture in a greased 9-inch square pan.
Bake in a 350 degree oven for 30-35 minutes.
Loosen edges from sides of pan as soon as they are removed from the oven. Cool slightly before cutting into squares. Serve warm, or freeze to use later.
If using frozen squares, reheat at 400 degrees for about 20 minutes (or until heated through).
Serving a larger crowd? Double the recipe and bake the spinach squares in a 9 x 13-inch dish.
Be sure that the spinach is squeezed very dry before adding it to the rest of the ingredients. To do so, I like to place the cooked spinach in a dish towel and wring it out over the sink. You'll be amazed by how much water comes out!
Grate the cheese by hand, rather than purchasing a package of pre-shredded cheese. This extra step is worth the effort, since the hand-grated cheese melts better (and tastes better)!
If freezing the squares, be sure to allow them to cool completely before wrapping.
Want to use fresh spinach instead of frozen chopped spinach? I have never prepared the recipe with fresh spinach myself, but a reader has tested it and commented below. See her note if you'd like to give it a try!
Can you freeze spinach squares?Yes! This make ahead appetizer can be baked in advance, and then wrapped tightly and frozen for up to 2 months.How to Reheat Spinach Squares:To reheat frozen spinach squares, place the frozen squares in a 400-degree F oven for about 20 minutes.