I put too much cayenne pepper in my split pea soup. Is there a way to tone it down please?

Sometimes lime or citric taste helps counter spice. Depends in your soup, try on a small portion first.

Thank you everyone. I had heard about the potato, but I thought that was to make something less salty. As it turned out, the soup was overly thick anyway, so as I gradually added water to it, it seemed to turn down the heat. Thanks everyone!!!

Heavy cream.

I agree with Janet S on adding potatoes. Yogurt will cut the heat too. Add a spoon of plain yogurt to each bowl when serving.

Add a potato.

Can you add more of everything else till it tastes the way you want?