Squeeze the excess water from the spinach and put it in a large mixing bowl. Add the remaining ingredients and mix well by hand.* Form the mixture into 1-inch balls, either by hand or with a small ice cream scoop. Place the balls closely together on a baking sheet.
Cook in the top half of the oven until firm to the touch, about 20 to 25 minutes. Let cool 5 minutes, and then transfer to a platter and serve immediately.
Wearing latex gloves while mixing and forming the balls is suggested.