Turn the muffin tin upside down and it makes a good cooling rack. I do this all the time.
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When you need a cooling rack for a baking sheet full of cookies or a cake pan just removed from the oven, remove one of your stoves burner grills and set it on the counter top to set the cooling pan on top of it, so air can circulate beneath it.
I discovered that my cooling rack fits perfectly on the kitchen sink. It works well for draining grapes after they have been rinsed. When they stop dripping, I can move the rack out of the way and let them sit until they are ready to put in a bowl and munch on.
Check out these photos.
This is a great way to cool down a pan from the oven. My husband came up with this - AMAZING! He pulled 4 tablespoons out of the drawer turned them upside down and Voila!