1. Preheat oven to 375°F. Mist 2 24-cup miniature-muffin tins with cooking spray.
2. In a bowl, mix flour, baking powder, cinnamon and salt. In a separate bowl, whisk eggs, milk, oil, sugar and vanilla. Stir dry ingredients gently into milk mixture. Fold in berries.
3. Spoon batter into muffin tins so they're 3/4 full. Bake until a toothpick inserted into center of a muffin comes out clean, 15 to 20 minutes. Let cool in pans on wire racks for 5 minutes, then turn muffins out onto racks. Serve warm.