In a large bowl, whisk eggs, applesauce, honey and vanilla until combined. Add oats, flaxmeal, cinnamon, baking powder, nutmeg and salt and mix to combine.
Pour milk substitute over mixture and whisk until incorporated.
Line two 12-cup muffin pans with paper liners and spray liners generously with cooking spray. Distribute oatmeal mixture evenly into muffin cups, about 1/4 cup each. OR do what I did and oil 8 ounce wide mouth canning jars. Put 1/2 cup mixture into each jar. Sprinkle desired toppings over the muffin cups if using.
Bake at 350 degrees F for 30 to 35 minutes or until a tester comes out clean.
Remove from oven and cool in pan on wire rack for a few minutes before transferring to cool completely on wire rack. Once completely cooled, store in an airtight container or zip-top bag and freeze. To reheat, microwave on high for 45-60 seconds.