Preheat oven to 325 degrees F. Butter the bottom and sides of a 9-by-13-inch baking pan. Put a long piece of parchment paper in the bottom of the pan, letting the parchment extend up the two short sides of the pan and overhang slightly on both ends.
In a large bowl combine oats, almonds, pecans, pumpkin seeds, sunflower seeds, wheat germ, flax seed, cinnamon and salt; set aside.
In a small saucepan over medium heat, melt the butter and honey together. Pour over the oat mixture and stir until well combined.
Spread the granola evenly in a thin layer on a large baking sheet. Bake, stirring every 5 minutes to keep from sticking or burning, until golden brown and crisp, about 20 minutes. (Do not overcook; the granola will crisp more when cooled.)
Cool the granola on the baking sheet on top of a wire rack and stir in the raisins. When the granola is completely cooled, place in a large bowl.
In a small saucepan over medium-high heat, bring the brown sugar, corn syrup and peanut butter to a boil. Cook and stir for 30 seconds, then pour over the toasted oatmeal mixture, stirring to coat well. Cool slightly then stir in chocolate chips. Press into the prepared baking dish and let cool completely and harden before cutting into rectangles.