Oven Temperature

I have been satisfied with the breads and cookies I have been baking.  This week I tried baking danish and they didn't do so good.  The recipe called for the oven temp. 350 degrees for 12-15 minutes.   At the end of 15 minutes my danish did not looked like they were done.  I added 3 min and 5 min and still they looked raw.  I thought that my oven might be the problem.  

I tested my oven by placing a Kitchenaid SS frying pan in the center of the oven.  I placed my oven thermometer in the middle of the frying pan.  (I used the KA frying pan because they have a thick base and heavy).   I also used an infrared thermometer.  I set my oven for 400 degrees and checked it every 5 minutes.  The temperature increased and stabilized at 400 degrees.  My oven dial was set on 400 degrees.   There was nothing wrong with my oven.  Why didn't the danish bake as they should?

Normally I used a thin bread pan, aerated baguette pan, or bake on a stone and all is well with each method.  I also bake cookies using a heavy duty pan.  I used the same pan for the danish.   I placed the heavy duty pan in the center of the oven and set the temp for 350 degrees and using the KA frypan and two thermometers confirmed the oven temp at 350 degrees.  Then I removed the KA pan and place my heavy duty baking sheet in the center of the oven.  I checked the temperature of the pan and found that after 15 minutes in the oven the surface temp of the pan was only 250 degrees with the oven temp at 350 degrees.  

The cookies I bake using the HD pan are thin and a soft sugar cookie.  I never noticed the temp difference because my cookies always came out great.    Apparently the danish did not bake because of the low temp of the HD pan.  

Comments appreciated, thanks.