Okay, first of all, stay away from the Ina Garten fritatta recipes. What she is making is NOT a fritatta, it is a soufflé! A fritatta has no flour, no baking powder or soda, and no milk or cream. A fritatta is eggs, with nothing added except vegetables, meat, and cheese. A classic fritatta also has potatoes, cut into small cubes and browned before adding them to the eggs.
Fritattas are NOT baked in the oven. That would be quiche! A fritatta is cooked on top of the stove until the bottom is lightly browned, then you slip it under the broiler to finish the top. Once the top is lightly browned like the bottom, you can add a cheese of your chioce and use the broiler to melt it, or leave it under even longer to make it brown and bubbly, like a pizza.
I told you I was a fritatta makin' fool, so please, do not desecrate my sacred fritatta!