Has anyone ever double muffin pan in each other while baking to keep them from browning too much on the botom?I use a 24count muffin pan now and it seemed to work when I used my reg 12 count pan

My cupcakes never brown on the bottom... I use a wilton pan. Are your pans extra thin? I might invest in another pan kind if they are browning your cupcake bottoms.

You can put a cookie sheet on your lower rack and your muffin pan on your middle and that will distribute the heat better. FYI this also helps in decreasing the dome on cakes and cupackes so if you do this, you will get flatter cupcake tops