Preheat the oven to 375°F (190°C) and lightly grease a 12-cup muffin pan.In a large bowl, add ½ cup unsweetened apple sauce, 1 cup Greek yogurt, ¼ cup honey, 1 large egg, and 1 teaspoon vanilla extract. Whisk until smooth and creamy.
Add 1½ cups rolled oats, 1½ teaspoons cinnamon, 1 teaspoon baking powder, and a pinch of salt. Stir well until all the oats are coated and no dry oats remain.Stir in 2 medium apples (chopped) and ¼ cup raisins (if using).
Spoon the mixture into the muffin pan, filling each cup almost to the top.
Bake and cool: Bake at 375°F (190°C) for 20–23 minutes, until the tops are lightly golden and the centers feel set. Let the cups cool in the pan for about 15 minutes, then run a small knife around the edges and lift them out.