Spinach Cheese Pita (Spanakopita)

also view my recipe here
INGREDIENTS (makes 9"x13" pan)
8 oz. phyllo (filo) dough thawed [in freezer section of grocery store] (I use the 1 lb. box that is divided into two 8 oz. packages - each containing 20 layers).
1 carton (24 oz.) cottage cheese
1 pkg. (8 oz) cream cheese, softened
1 lb. brick cheese, grate, or chopped 
4 eggs (separated)
1 pkg. frozen chopped spinach, defrosted and squeezed dry
1 stick butter, melted
Pam (cooking spray)

Preheat oven to 365°.
Prepare filling:
     Mix together well: brick cheese, cottage cheese, cream cheese, spinach, and egg yolks.
     Beat egg whites until stiff and fold into cheese mixture.
Assemble phyllo:
     Spray 9” x 13” pan with Pam.
     Put one layer of phyllo dough into pan. Brush lightly with melted butter. Repeat 9 more layers.
     Pour filling and level out.
Repeat again 10 layers of phyllo dough brushing as before with butter. Brush the top layer too.
With sharp knife, score top layers to the size of pieces to be cut.
(note: the above may be refrigerated overnight)
Bake at 365° for 45-50 minutes (70 min., if previously refrigerated)

Should be golden brown on top.
This is like a souffle so it will be puffy at first, then will settle.
Wait a few minutes before cutting. Best Served warm:)