center of cakes not cooked!!!

You need to check the centers with a wooden toothpick. Insert the toothpick into the center and pull it out. If it comes out clean it's done.

Just guessing...maybe you're not preheating the oven long enough. Or it could be that too much hot air is escaping while you put the second cake in. If so, when the door closes, the oven superheats to recover, and this can make the outside of the cake get done before the middle. Or in addition to either or both of those things, the oven thermostat might be off a few degrees. My opinion is that you should be able to successfully bake two cakes without the centers being under done.

don't take this wrong but simple physics say that an oven of x and x size cooks ONE cake at x and two cakes at X+. Mass is something to be considered. Try giving em an extra 5 minutes and doing a toothpick check, it may take longer. you are totally right to expect to be able to cook two cakes at once, but unless you have a commercial oven your not going to do it in the same amount of time. best of luck.

A couple things I have found is:
- Use double action baking powder. Single action and baking soda only work after you mix them in with the other ingredients, specifically acid based, and stop working after a period. Double action baking powder will work both at the beginning and when the baking powder gets to a certain temperature.
- When I put in two or more quick loaves or cakes I make sure they are as far apart from each other as I can get them while staying away from the walls of the oven. I also put them on baking sheets in the middle of the oven on the same rack.
- If you must look, don't open the oven door until at least 20 minutes into the bake.
- When I use a wooden skewer, before you puncher the cake give it a tap on the top. if it wiggles or moves wait 10 minutes and try later. If you puncher it too early the centre will fall. And be quick.
- When using the skewer I put it in on an angle where I pass through the centre and middle of the cake. When I bring it out I runit through my fingers to see if there is any dough that I couldn't see on the skewer.
- Rotate the cakes in the oven when the cakes are firm enough to ensure even cooking and an even amount of colour. Visualize it first and then do it quickly.

internal temp

get an instant read thermometer and check the center of your cake.
Make sure you hit around 195 to 205 degrees F.

not a big fan of toothpicks.

this will insure the starches have gelled and set, the eggs are cooked, the dehydration has taken place.

Sounds like they need more time, typically if still soft in the centre at least 10 minutes more.

go to a kitchen supply store and get an in oven thermometer. :D

Never go by the time specified in a recipe for baking--there are too many variables that can alter your optimal baking time: your oven temp, how far apart you place the cakes, etc.

Bake them until they are done. That sounds simplistic, but if they aren't set in the centers when you check them, bake them for longer. If the tops of your cakes are getting a little dark, cover them loosely with foil--just lay a piece on top, don't try to crimp it or fold it over the edges of the pan.