Combine all ingredients (except optional toppings) in a jar or a container that seals well (select something that has a volume of 16 ounces or larger). Stir with a spoon until everything is well incorporated and there are no lumps. Seal the container and shake vigorously for about 30 seconds.
Place the sealed container in the fridge for at least 4 hours or ideally overnight.
To serve, give the oats a good shake or stir. Top with whipped cream and crushed pecans (if using).
Notes
Consume within 2 days of preparing for best quality.When buying protein powder I like to select protein powder with minimal ingredients and no added sugar or artificial sweeteners, but you can use your favorite vanilla protein powder. If vegan, you will want to find a dairy-free option.