Preheat oven to 350 degrees Fahrenheit and adjust oven rack to the middle position.

Cut a sheet of parchment paper in half and then line bottom of an 8x8 inch pan with 1 sheet of parchment. Add the second sheet of parchment over the first sheet, in the opposite direction. The sheets should cross each other and have a small overhang. This will facilitate the removal of your bars from then pan. Alternatively, you can line the pan with aluminum foil the same way. If, and only if you are using foil, spray a light coating of vegetable spray.

In a medium bowl, add flour, chopped walnuts, oats, sugar, and salt. Mix with your hands or with a fork to combine. Stir in the melted butter and mix with a fork until the mixture is well coated with the butter and all dry ingredients are well moistened.

Spread half the oat/walnut crumble mixture, covering the bottom of the pan. Press to form a thin crust that’s about ¼ inch in thickness. Mix apple butter, cinnamon, and ground ginger in a small bowl (or straight from the jar). Spread apple butter over walnut/oat crumble mixture evenly using a small offset spatula. Sprinkle remaining walnut/oat crumble mixture over the apple butter. You know, like an apple butter sandwich.

Place pan in the oven and bake until the crumble is a golden brown, about 35 to 40 minutes. Set on a wire rack and cool to room temperature. Resist the temptation to dip a spoon into the pan and eat warm. RESIST, I say! Use the parchment paper “handles” to remove bars from pan. Cut into squares and serve.

Makes about 16 squares.