When I'm baking this, I bake the gooey batter until it's firm (about 10 minutes) and then I lift it out of the pan by the parchment paper and bake it longer on the center rack. I do this because I find it makes the crust crisper. This step is totally optional. The kids like a chewier crust so they don't bother removing it from the pan, they just bake it for a whole 25-30 minutes right in the pan, then top it and continue to bake until the cheese is melted