01 - Preheat oven to 350°F. Line a standard 12-cup muffin tin with paper liners or grease thoroughly with cooking spray.
02 - In a large bowl, whisk together rolled oats, baking powder, ground cinnamon, and salt until evenly distributed.
03 - In a separate bowl, combine applesauce, milk, eggs, honey or maple syrup, melted coconut oil or butter, and vanilla extract. Whisk until smooth and fully blended.
04 - Pour the wet ingredients into the dry ingredients. Stir with a spatula or wooden spoon until all dry patches are incorporated and a thick batter forms.
05 - Gently fold in your choice of optional add-ins such as berries, diced apples, chopped nuts, or chocolate chips, being careful not to overmix.
06 - Divide the oatmeal mixture evenly among the 12 prepared muffin cups, filling each approximately 3/4 full. Use a spoon or ice cream scoop for consistent portioning.
07 - Bake for 22 to 25 minutes, or until the cups are set in the center and lightly golden on top. Remove from oven and let cool in the pan for 10 minutes before transferring to a wire rack.
08 - While oatmeal cups cool, mix Greek yogurt with honey or maple syrup in a small bowl until sweetened to your taste.
09 - Once oatmeal cups have cooled completely, top each with a generous spoonful of sweetened Greek yogurt and garnish with fresh berries or sliced fruit. Serve immediately or store for later.