Prepare Batter: Preheat oven to 350°F (175°C) and line a muffin tin with 12 liners. In a large bowl, whisk flour, oats, baking powder, baking soda, and salt. In another bowl, mix honey, Greek yogurt, applesauce, eggs, and vanilla until smooth.
Combine: Gently fold the wet ingredients into the dry mixture until just combined. Carefully fold in mixed berries.
Bake: Spoon the batter into the muffin tin, filling each cup ¾ full. Bake for 18-22 minutes until golden and a toothpick comes out clean. Cool before serving.
