There are four main reasons why your pumpkin bread hasn't cooked in the center. First of all, you may have used too much pumpkin puree, which adds excess moisture. Second, you may have over-mixed the batter, which causes the bread to deflate. Third, you may have used a baking loaf that is too small, meaning that the bread couldn't cook evenly. Last but not least, you may have baked your chocolate chip loaf for too little time.