Is a little oven less hot than a bigger oven? Some months ago, I found a recipe for cookies and made them in a big oven; they were delicious and cooked very well (soft cookies) at 180 °C (356 °F) for 7 minutes.

I recently tried the recipe again, but I have no longer a big oven, so I used my little one (with heat source at the top and bottom).
The cookies were still almost liquid after 15 minutes, and I though that was my oven that was too old and not keeping a good temperature; I tested on another oven that is new, and I got the same result.

Does the little oven heat less than the big one? If yes, what do I need to do to adjust the temperature and/or the time? If not, what am I doing wrong?

The recipe is:


  
  125 grams of soft butter
  125 grams of brown sugar
  175 grams of white flour
  one egg
  1 cc of baking powder 
  100 grams of chocolate chip
  
  
  Mix all except chocolate chip. When you have a homogeneous substance, add the chocolate chip.
  Bake them 7 minutes at 180 °C. they're still very soft after that delay but they will harden.
It could be that your oven's temperature control is off somewhat. Ovens aren't exactly scientific instruments, so you can't be sure how accurate they are with this kind of thing. 

Get a decent oven thermometer and go by that rather than the temperature knob. You might be surprised. Mine runs about 10-15 degrees less: when I set it to 180 on the dial, it's often about 165 on the thermometer.