1 package frozen spinach, thawed and drained well
8 ounces whole-milk ricotta cheese
3/4 cup plus 2 tablespoons of grated Parmesan cheese, divided
Preheat the oven to 350 degrees Fahrenheit.
Butter a 9-inch square baking dish.
In a large bowl, beat together the spinach, eggs, ricotta, and 3/4 cup Parmesan until well blended. Pour into the baking dish and smooth the top. Sprinkle the 2 tablespoons of Parmesan on top.
Bake at 350 degrees Fahrenheit for 45 to 50 minutes or until the frittata is slightly puffed, set in the center, and lightly browned around the edges.
Let cool for ten minutes. Run a knife around the inside of the pan rim and remove the rim. Cut into wedges to serve.