A double dose of vanilla—in both the yogurt and vanilla extract—makes this easy, baked breakfast dish irresistibly rich and fragrant. Serve at brunch, or cut into slices and pack for breakfast, to eat warm or cold. If you prefer, use other frozen fruit like sliced peaches or pitted cherries instead of berries.
Preheat oven to 375 degrees. Oil a (9-inch) pie pan with cooking spray; set aside. In a large bowl, stir together berries, oats, pecans, baking powder, salt and apple. In a medium bowl, whisk together milk, yogurt, syrup, vanilla, egg and yolk; stir into oat mixture. Transfer to prepared pan and bake until firm and golden brown on top, about 50 minutes. Cut into slices and serve.