Preheat oven to 350 degrees F (180 degrees C).
Mix together All-Purpose Flour (1 1/2 cup), Old Fashioned Rolled Oats (1 1/2 cup), and Brown Sugar (1 cup).
Cut Unsalted Butter (3/4 cup) into pieces.
Knead flour ingredients and butter together until you have a smooth dough.
Grease a 9x13-inch pan with Unsalted Butter (to taste).
Split the dough in half. Press one half into the baking dish so it forms an even layer.
Spread the Raspberry Jam (1 1/2 cup) on top.
Sprinkle the remaining dough over the jam. Bake for 35 minutes, and cover with aluminium foil if you notice the top is getting too brown.
Take the pan out of the oven and let it cool down. Cut into bars and enjoy.