Preheat oven to 375, use a little of the butter to grease a jelly roll pan.

In a food processor pulsate together 1 cup of the butter (cut into chunks before adding to the food processor), 1 2/3 cups flour, 2/3 cup of the sugar and 1/3 cup oats. Pulsate until combined into a mealy mixture. Press into the prepared pan.

Spread the jam over the prepared layer. (If adding fruit - now is when you would add it)

In the food processor process the remaining ingredients (1/2 cup butter, 1/3 cup flour, 1/3 cup sugar, 2/3 cup oats) until a crumbly mixture, then sprinkle over jam.

Bake for 25 minutes or until edges are golden brown, then remove from oven and allow to completely cool before cutting into squares (I cut big squares and got 32, but you could easily cut these into small squares for more!)