My cookies had been bake for almost 13 minutes ...but my cookies didn't flat and it had blacken on top ... so what function that is suitable for baking cookies ... ?? Is upper-lower or upper-convection-lower or what ??
A convection oven uses a fan that circulates the air so it shouldn't matter which self you use in the oven. I suggest you use the bake setting which only uses the lower heating element and not the roast setting which uses both the upper and lower element. When I bake cookies I baked it 25 degrees lower in my convection oven. Hope that helps!