2 servings will fill a 16 oz mason jar. We’ve been making these for a few weeks now on Sundays, as our breakfast throughout the week. For the cookies we’ve been using the chocolate kind, crumbling 3 into the jar and leaving the 1 on top for a little bit of that cookie crunch. I recently bought the crunchy Biscoff cookie butter and am curious to try that in this recipe as well. We’ve been mixing the cookie butter in with the other ingredients, and have yet to try it as a single layer on top. I’m certain it will still taste as good.