Preheat oven to 325 degrees F. Lightly grease an 8 by 8-inch baking dish and set aside. In a small saucepan melt butter with honey over low heat, stirring. In a large bowl stir together oats, almonds, pecans, pumpkin seeds, sunflower seeds, cinnamon and salt. Pour butter mixture over oat mixture and stir until combined well. On a large baking sheet, spread the granola evenly in a thin layer. 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 in the pan on top of the stove and stir in the raisins. When the granola is completely cooled, place in a large bowl. Combine the brown sugar, corn syrup, and peanut butter in a small saucepan over medium-high heat. Stir constantly until the sugar is dissolved and the mixture is at a boil. Remove from the heat and pour the mixture over the granola, stirring to coat well. Cool slightly and press into the prepared baking dish and let cool completely and harden. Cut the mixture into ten 1 1/4 by 4-inch bars and serve at room temperature. (The bars may be kept in an airtight container at room temperature for up to 1 week.)