Preheat your oven to 375°F (190°C). Spray a little oil onto a muffin tin and set it aside.
Put all of the liquid ingredients into the blender (banana, apple sauce, almond butter, sweetener, milk, and vanilla) and blend for a few seconds until you can no longer see chunks of the banana.
Add 1 cup of whole oats and blend again for a few seconds.
Add the remaining 1 cup of whole oats, baking powder, baking soda, and salt and plus the blender a few times until all of the dry ingredients are mixed into the batter. (You may have to stop and scrape the edges of the blender.)
You can stir in 3/4 cup berries or chopped fruit (or 1/2 cup chocolate chips) to the batter if you want to make them all the same flavor. (For different flavors in the same batch, pour the batter into the muffin tins and place 1 tablespoon of add-ins to each muffin.)
Pour the batter directly from the blender into the prepared muffin tin filling the cup about 3/4 of the way to the top. (I sprinkle a few oats on the top before baking to make them look prettier.)
Bake at 375°F (190°C) for 18-20 minutes until golden brown on the top. Allow cooling for about 10 minutes before taking them out of the muffin tins.
Notes
Chocolate Chip - stir in 1/2 cup of mini chocolate chips after blending. Sprinkle a few extra chocolate chips on top of the muffins before baking.Banana - chop up an additional banana into bite-sized pieces and stir into the batter after blending.Raspberry - add 3/4 cup of raspberries to the mixture after blending.Blueberry - add 3/4 cup of blueberries to the mixture after blending.Strawberry - chop up 3/4 cup of strawberries into small pieces and add them to the mixture after blending.Apple Cinnamon - add 1 teaspoon of cinnamon along with the dry ingredients before blending. Then chop up 3/4 cup of an apple into bite-sized pieces and stir into the batter after blending.Double Chocolate - add 1/2 cup cocoa powder to the batter plus an additional tablespoon of sweetener for chocolate oatmeal. Stir in 1/2 cup of mini chocolate chips after blending and sprinkle an additional 1/4 on top of the muffins before baking.