Preheat oven to 350 degrees Fahrenheit. Spray an 8″x8″ baking pan with non-stick cooking spray or lightly grease with butter and set aside.
Add flour, sugar, walnuts and butter to a medium bowl. Using a pastry blender or a fork, combine butter with dry ingredients until mixture is combined. Alternatively, place ingredients in a food processor and pulse a few times until combined.
Reserve 1 cup of the mixture and press the remaining mixture on the bottom of prepared baking pan to form crust. Press until mixture is firmly in place.
Spread jam on top of crust and sprinkle with reserved flour mixture.
Bake for 35-40 minutes until golden brown.
Cool on a wire rack completely. Cut into desired size squares.