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 mixing bowl, whisk together rolled oats, baking powder, ground cinnamon, and salt until evenly distributed.
03 - In a separate bowl, whisk together applesauce, milk, eggs, honey or maple syrup, melted coconut oil or butter, and vanilla extract until smooth and fully combined.
04 - Pour the wet ingredients into the dry ingredients. Stir with a spatula until all ingredients are fully incorporated and no dry patches remain.
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 prepared muffin cups, filling each cup about three-quarters full.
07 - Bake for 22 to 25 minutes, or until the cups are set and lightly golden on top. Remove from oven and let cool in the pan for 10 minutes.
08 - Transfer the oatmeal cups to a wire cooling rack and allow them to cool completely before adding toppings.
09 - In a small bowl, mix the Greek yogurt with honey or maple syrup to taste. Stir until smooth and well combined.
10 - Top each cooled oatmeal cup with a generous spoonful of the sweetened Greek yogurt. Garnish with fresh berries or sliced fruit before serving.