Preheat the oven to 350F. Place a 12-inch square of parchment paper over an 8-inch square baking dish and press it down onto the bottom and up the sides of the dish.
In a large bowl, stir together the oats, flour, flaxseeds, brown sugar and salt. Stir in the peanut butte and melted butter. Press the oat mixture into the prepared baking dish, reserving 1/2 cup for topping. Spoon 4 lines of jam across the top of the oat mixture. Sprinkle the remaining 1/2 cup of oat mixture over the jam.
Bake for 30 to 35 minutes, or until slightly browned and firm.
Cool completely, at least 1 hour. Cut into squares.