i make my cupcakes and put two dozen in the oven i check them with toothpicks. and they still are gooey in the center and i keep an eye on them, by the time i get them out of the oven when the center is done the bottoms are over cooked. some are alot and others arent too bad. how can i avoid this. i use a gas oven. i know it has a factor cause since we moved my cupcakes have not been the same.

Hi. Try cutting down on the temperature. I have a smaller oven and when baking cakes/ cupcakes, I cut down on the temp. It increases the cook time but it's worth it. I hope this helps.

Are the on the middle rack? I'm sure they are but I gotta ask.
Is it possible that you bottom element is too hot? I'm not really sure how that work with gas. I have a gas oven and my one back corner runs hotter than the rest.
I also bake my cupcake at a lower temp for longer. 325

perhaps there's a trick for insulating the bottom of the pan or better distributing the heat ... maybe putting a pizza stone on the bottom rack? or maybe putting a silicon baking mat on a baking sheet, then putting the cupcake pan on top of that? i dunno!

Try baking on the top rack and also put a thermometer in your oven. My burn too if I put them on the bottom rack.

Another possibility in addition to all of the above... place a cookie sheet under them to help insulate... maybe two if you have a faulty oven.