Preheat oven to 350 degrees F (175 degrees C). Line a 9x13-inch baking dish or jelly roll pan with parchment paper.
Mix oats, walnuts, brown sugar, dried fruit, all-purpose flour, whole wheat flour, wheat germ, cinnamon, and salt together in a bowl.
Whisk oil, honey, egg, and vanilla extract together in a separate bowl; stir into oats mixture until batter is just mixed. Spread batter into the prepared baking dish.
Bake in the preheated oven until golden brown around the edges, 20 to 25 minutes. Cool slightly on a wire rack; cut into 12 bars while still warm using a pizza cutter.
