how do you make sour milk? can you use buttermilk instead?

I always have buttermilk on hand but the powdered buttermilk is a great pantry staple for recipes like this!

Yes you can ! Enjoy !

You can also use a teaspoon of white vinegar to a cup of milk. Mix it in and let it sit 15 minutes.

Made it last week (full disclosure, someone made it for me) with a tablespoon of lemon mixed with the milk, but I would think buttermilk is an ok substitute. Came out great, and I'd recommend just sticking with a dusting of powdered sugar, it doesn't need more than that!

I've made it a couple of times with buttermilk - it was great. If buttermilk isn't handy, you can also add one tablespoon white vinegar to one cup milk and let it sit a few minutes.