Any wise and experienced bakers out there who can tell me why my biscuits are burned underneath but still uncooked on top?

[worriermum]

I made some chocolate chip cookies (the BBC Good Food recipe) and they were nice but blackened around the edges while still pale and doughy on top. How can I prevent this from happening again?

Ta in advance

Did you have the oven too high? Or the shelf too low in the oven?

do you have a fan oven? You need to reduce the temperature if you do.

The shelf WAS lower in teh oven. But I did reduce the temp for my fan oven. Sorry to be thick, but why would a lower shelf result in blackened bottoms?

Depends on the oven. If it is a fan assisted it shouldn't make any difference. My ancient oven has the heating spirals at the top and bottom of the oven so if I put anything too low down, it burns underneath.

This happens in my fan oven too; the base of cookies or cupcakes is always overdone before the top is brown.
I will try an even lower temperature; I do lower it about 20 degrees though.

Do you have the choice of not using the fan oven? If so I would suggest dont use it for baking.I use the conventional top oven as the results are more consistent.

I started to get this when we had a new fan oven. I make a lot of biscuits.

In the end I got something like this which is double thickness with air between. It works.

I've got a couple of these. As Katisha says, this sort of stuff does stop the bottom of biscuits from burning.

Oven too hot.