Preheat the oven to 325°. Lightly spray a loaf pan with nonstick cooking spray.
In a small bowl, whisk together the flour, baking soda and salt. In the bowl of a stand mixer, cream together the shortening and sugars. Add the mashed banana, peanut butter, applesauce and vanilla, and continue mixing. Slowly add the flour mixture and blend until smooth.
Spread half of the batter in the prepared pan. Drop 1½ tablespoons of jam on top and swirl the jam through the batter with a knife, covering the surface evenly. Spread the remaining batter on top. Drop the remaining 1 tablespoon of jam on top and swirl through the batter with a knife.
Bake until a toothpick inserted in the center comes out with moist, crumbs attached, 60 to 70 minutes. Let cool before serving.