What makes a cake gummy in the middle?

I made a carrott cake and it was gummy in the middle like I forgotton some ingredients. I threw it out Today I make zuchinni bread and it done the same thing What makes them gummy in the middle? It is not my oven I checked that already.

It has to be that the heat is baking the outside before it reaches the interior. Try a bit lower temp and more time. If you can arrange it in doughnut shape like a bunt cake, that may help.

Rob's right. It's not cooking completely in the center. You can try as he says, or also slightly reduce the amount of liquid in the recipe. To test if it's done, you can stick a toothpick in the center. If it comes out dry, the center is done. If it comes out wet, the center in't done.