Baking – Is 440° F too hot for an oven temperature

My guess:

With a little oven you probably don't preheat as long, and when you open the door you let ALL the hot air out. You need to reheat the air in the oven after the cookies go in for them to cook. Because the hot walls and rack are much smaller (and probably not as well heated to start with), it's harder for them to reheat the inside of the oven.

So the temperature is lower when you start the cookies. Some (maybe a lot) of the cooking time is spent getting the oven, the baking sheet and the air back up to temperature. Cooking them longer or at a slightly hotter temperature should help with this.

It's definitely a sign that the oven is cooking too hot somewhere; the under-done tops and middles are the give-away. I suspect your oven has a malfunctioning thermostat, which is quite common. Try setting temperatures 50 degrees below suggested, and see if it solves the problems. Failing this, purchase an oven thermometer to check it.

Another possibility is that there is poor airflow within the oven. In this case, hot air is heating the bottom of the pan, but cannot get around the edges of the pan to heat the top of the baked good. The solution to this is usually to use a smaller pan, and ensure only one pan at a time is loaded into the oven. My oven has problems of this nature when I try to bake in both racks with half sheet pans.