I looked through the recipe index, and couldn't believe there were no recipes for jam bar cookies - they're some of the easiest cookies to modify for fat content. This was a recipe from http://www.realsimple.com, tinkered-with only slightly.
1 3/4 cups flour 1 cup light brown sugar, firmly packed 1 tsp salt 1/2 tsp baking soda 1/4 cup light margarine (I use Smart Balance Light) 3 tbsp orange juice 1 1/2 cups quick oats 2 tbsp lemon zest (that's not a typo - lots of lemon!) 1 1/2 cups (or a 12-oz jar) raspberry jam
Heat oven to 350 degrees, and spray a 13x9 pan with cooking spray.
Place the flour, sugar, salt, baking soda, and margarine in the bowl of a food processor, and pulse several times to combine. Add the orange juice, and pulse a few more times, until the ingredients form a crumbly dough. Add the oats and lemon zest, and pulse quickly twice more to combine.
Press 2/3 of the dough firmly into the prepared pan. Spread the jam evenly over the crust. Sprinkle the remaining dough over the jam, pressing lightly. Bake until golden brown, about 25 minutes. Cool completely, about 2 hours. Cut into 24 bars.
For bar cookies like this, fruit juice makes an excellent substitute for most of the fat (the original recipe calls for 3/4 cup butter!) - when baked, you get the same crisp texture that you would have gotten with butter. You could actually omit ALL of the margarine, adding another tablespoon or 2 of orange juice, but I used SOME margarine for taste.