Thanks to everyone who posted suggestions about the use of parchment paper (remove or not). I ended up not removing and the bottom was just fine. I used whole wheat pizza dough I bought at Trader Joes - it was a little "flat". Next time I'll make my own.First a layer of pizza sauce... then mozzarella... then sliced portabellos.. then pepperoni... then Quattro Formaggio from Trader Joe's which is a blend of provolone-asiago-parmesan-fontina.. and topped with slices of red, orange and yellow sweet pepper... Baked at 500 for 15 minutes...Before.... During.... After....