This. I've been eating cold overnight oats for probably the last 8 years. When I switched to a high protein diet, I customized my recipe to maximize the protein.
226 g fat free plain Greek yogurt
480 g Mootopia fat free milk
60 g plain egg white protein powder
9 g powdered sugar free jello, flavor of choice (I like the cheesecake)
Splash vanilla
135 g oats (I like the Trader Joe's rolled oats with ancient grains and seeds - just make sure you DON'T use quick cooking oats)
36 g chia seeds.
Add in ~140 g of your fruit of choice and whatever flavors you like. Lately I've been doing fresh peaches and cardamom. I also do blueberry+cinnamon, cherry+chocolate (using cacao powder), and carrot cake (my fave - the shredded carrots give it a fantastic texture). Been thinking about coming up with a banana bread flavor.
Top with something crunchy. Lately I've been into pomegranate seeds and the Elizabeth sweet and salty granola. Toasted almonds or pecans, cacao nibs, and bare banana chips are all good.
Recipe above makes 4 servings of about 270 g each, 310 cal and 33 g protein, 31 g carbs, 6 g fat without the crunchy toppings. You could up the egg white protein if you want (or use some other kind of protein). Could also use higher fat yogurt and/or milk.