Can you use milk instead of buttermilk in whoopie pies?

While milk can be substituted for buttermilk in some recipes, I would not recommend using milk in whoopie pies. Buttermilk is a fermented dairy product that gives baked goods a tangy flavor and a tender crumb. Milk, on the other hand, is not fermented, and it will not produce the same flavor and texture in whoopie pies. If you do not have any buttermilk on hand, you can make your own by adding 1 tablespoon of white vinegar to 1 cup of milk and letting it sit for 5-10 minutes before using it in the recipe.