Step 1

Preheat oven to 375 degrees F (190 degrees C).

Step 2

Place spinach in a steamer over 1 inch of boiling water, and cover. Cook until tender, about 2 to 6 minutes. Drain and press to remove all water. Meanwhile, heat oil in a large skillet over medium heat. Saute onion until tender, but do not brown. Stir in cooked spinach and continue cooking until all moisture has evaporated. Remove from heat and cool to room temperature.

Step 3

In a large bowl combine feta cheese, Swiss cheese, Parmesan cheese, eggs, parsley and cinnamon. Stir in spinach and onion mixture.

Step 4

Brush the bottom of a 17x11 inch jelly roll pan with butter. Place 1 sheet of dough in the bottom of the pan; brush with butter. Continue to layer 13 more sheets of dough, brushing every other sheet with butter. Spread spinach and cheese mixture over dough. Continue layering with remaining dough, brushing every other sheet with butter. Tuck edges of dough under. Brush top sheet with butter and, using a sharp knife, score top layer into diamonds.

Step 5

Bake in preheated oven for 40 minutes, or until golden brown.