I am working on a wedding cake order with six (!) half sheet cakes and a tiered cake. I've made half sheet cakes before, but I don't use as much batter, so the cakes don't bake right to the top. This time though, the cakes are baking nice and high, which is good. Every time I test them, the middle is always done, the sides pull away from the pan and the top bounces back when I touch it.
However.
The last two cakes I just made, I decided to level before I wrapped them. After I levelled them, it looked to me like the middle is not as done as the rest of the cake. I am confused as to how my tester came out clean if they weren't done....they're not raw, but a little sticky to the touch.
Is this fairly normal though? I tasted it, and it tasted fine, just very moist. Should I leave them on the counter for a while, unwrapped, to see if that helps?

I often get that with my square and rectangle cakes too, despite my tester coming out clean. I've never had a problem with them like this, I've torted them and checked the middle and you find it's just the top half that usually looks like this. I've eaten them and certainly when you cut it you can't tell the difference.

Thanks!