Preheat the oven to 350°F. Lightly spray 12-cup muffin pan with cooking spray.
In a medium bowl, using a fork, separate the spinach into small pieces. Stir in the chopped jalapeno pepper and green onions. Spoon the spinach mixture into the sprayed muffin cups. Sprinkle the Parmesan over the spinach mixture.
In a separate medium bowl, whisk together the remaining ingredients. Pour into the filled muffin cups.
Bake for 18–20 minutes, or until a wooden toothpick inserted in the center comes out clean. Transfer the pan to a cooling rack. Let cool for 10 minutes. Using a thin spatula or flat knife, loosen the sides of the quiche bites.
Refrigerate leftovers in an airtight container for up to 5 days. To reheat, put 4–6 quiche bites on a microwaveable plate. Microwave on 100% power (high) for 45 seconds to 1 minute, or until heated through.