You're Stromboli are beautiful. I've tried to make a version of a Stromboli that I love: Spinach, Garlic, Mozz & Asagio. Every time I've tried I have a cheese blow out. I fill the center and fold the top 1/3 over the toppings. I fold in the sides almost like you would a spring roll or a burrito and then fold the bottom 1/3 over the "middle." so two layers of dough on top. I slit the top as you do. Now I've tried to put the overlapped thick dough on the top and slit it. And I've inverted it when I make two back to back and have a cheese blow out. I just bake one. If it blows out before I bake the second one - I flip it over and slit the other side (only the top side.) I've tried mixing the shredded cheese with the filling and below the spinach/garlic/asagio and above. Shredded and not shredded. as well as partially frozen small rectangles. I have also cut back the amount of cheese to a point where it's almost like spanikopita - very little cheese. The Stromboli that I spoke about in the beginning was actually called "Spinach Bread" However, I watched them being made on the bench and it's standard pizza dough (a NY ish dough round) with two moderate handfulls of cheese. They are about 24" long and baked on a screed in a deck oven. I have baked mine on parchment on soapstone as well as on parchment on a screen on soapstone. I use steel primarily for pizza now but have not tried parchment on steel as this leaking cheese vexes me. Any suggestions from the forum would be greatly appreciated. Here are some pics for reference.