Hi Shelby, a number of factors can contribute to wrinkly buns, and this isn't something we ever consider a grave error, but it might be worth trying to put the buns in the oven a little earlier, especially if you let them rise until they were quite large before baking. Buns that are slightly overproofed may still puff up nicely in the oven, but as the buns cool and release moisture, the rolls may shrink and collapse a little, causing wrinkles. Again, a lot of factors can play into wrinkles, so it can be hard to pin this one down, but hopefully this will help. 

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