Roughly 25 to 28 grams of protein per slice depending on your protein powder. Use whatever milk you've got (skim, 1%, 2%, or whole). Skim or 1% will keep this leanest macro-wise. Don't sub Greek yogurt for regular yogurt or you'll lose the thickness and the protein punch. If your pudding mixture isn't setting up firm, your protein powder is probably plant-based, which behaves differently. Add an extra tablespoon of sugar-free pudding mix to compensate.