Preheat oven to 350 degrees F, place cupcake liners into a 12 muffin tin and spray generously with cooking spray. Alternatively, you could use a silicone BPA-free muffin baking pan or individual silicone BPA-free muffin cups. Also, you could make the egg bake in an 8 x 8 baking dish lined with parchment paper and then cut into squares. DO NOT bake the egg muffins directly in the muffin tin, they will stick!In a large mixing bowl, whisk eggs and egg whites for 30 seconds. Add flax/chia seeds, feta cheese, onion (garlic) powder, salt, pepper and whisk to combine. Add quinoa, spinach, sun dried tomatoes and mix. Fill each muffin with egg mixture 3/4 full. If you have extra mixture bake in additional ramekins but do not overfill. Bake for 20 minutes, remove from the oven and let cool for about 10 minutes. Using a rubber spatula, loosen the egg muffins from the muffin tin and slide onto a platter. Serve hot (I like to add a few drops of Frank's RedHot Buffalo Sauce on top).