I have just begun my cookier career. I made a few dozen cookies, decorated and sold them. I have been running into a problem with my sugar cookies these past 3 weeks. I will have one batch come out beautiful, not burned, not raw but just right ( the perfect light shade, plump full look). The next batch of cookies will look raw/buttery at the bottom. Anything I cook after that comes out the same. Once I set the baking sheet on the cooling rack I can see the middle begin the get dark spots, once it cools I flip it and the bottom has "raw" or "buttery" looking spots. Any ideas on how I can stop this from happening? I did not take any pictures and it just happened last night AGAIN. Any help is appreciated.