In a large bowl, whisk together eggs, milk, hot sauce, cumin, salt, pepper, and lemon pepper.
In another large bowl, stir together the spinach, ricotta, sour cream, Parmesan, and cheddar cheese until it's well combined.
Add the egg mixture to the spinach mixture.
Spray your muffin tin liberally with cooking spray, then add the mixture to the muffin tins.
Bake in a preheated 375°F oven for 20 to 25 minutes. The frittatas should look puffed and lightly golden on top.
Let the frittatas cool in the pan for about 5 to 10 minutes. Run a small knife or offset spatula around the edges to loosen the frittatas, then lift them out of the muffin tin.