i am on my 3rd cook with the oven and desided to try some bread after the pizza. the temp on the floor of the oven was 425. I put the bread in and set the clock for 15 min. (time to come back and check on the progress) when I came back the bread was done... the temp inside the bread was 190...abd the top was black! it should have only been 1/2 done but it was wonderfully done in the center but burned on the top. all in only 15 min. what did i do wrong?