One of the biggest challenges in making panettone is keeping the top from collapsing as it cools. The secret here is to hang the loaf upside down for 1 1/2 to 2 hours immediately after removing it from the oven. This is simple when using a paper mold. Hold the mold upside down and slide 2 long bamboo skewers into the bottom of the loaf, through the paper mold and out the other side. Then drape the bread over a rack or other device where it can freely hang without the top of the loaf touching the counter. I put my loaf upside down in a tall pot.