Preheat oven to 350ºF. Line a 9-by-13-inch baking pan with foil; mist foil with cooking spray.
In a large bowl, mix oats, brown sugar, flour, wheat germ, cinnamon and salt, breaking up any lumps of brown sugar. Toss in raisins, apples and nuts. In a separate bowl, whisk maple syrup, egg, oil and vanilla. Pour maple syrup mixture into oat mixture and combine well, using your hands.
Press mixture into baking pan and bake until just turning golden brown around edges, 30 to 35 minutes. Place on a wire rack to cool for 5 minutes. Using a sharp knife, cut into bars in pan while still warm. Let cool further before removing from pan to rack to cool completely.