Don't skip whipping the egg whites — it's the secret to fluffy texture. Overmixing the batter will make them dense. Check your protein powder for sweetness and adjust liquid accordingly. Fill ramekins 3/4 full to allow for rising. Let rest 2 minutes before serving. Store leftovers in an airtight container in the fridge for up to 5 days. To reheat, microwave 30-45 seconds or toast in a toaster oven at 350°F for 3-4 minutes. Freeze wrapped individually for up to 3 months.