Preheat oven to 350 degrees.
Combine flour, both sugars, spices and salt in a large bowl. In a separate bowl, whisk eggs, oil, sour cream, molasses, ginger and vanilla together.
Dissolve the baking soda in 1 cup of boiling water. Whisk the hot water mixture into the wet ingredients. Fold wet ingredients into dry ingredients until combined.
Spray two loaf pans with nonstick cooking spray. Divide batter evenly between the pans. Bake for 30-35 minutes, until a toothpick inserted in the middle comes out clean. Cool before turning out onto a plate. Cut into cubes.
To make the bourbon cream, combine the heavy cream, sour cream, sugar and bourbon in a large bowl. Using a hand mixer, whip on high speed until stiff peaks form.
To assemble: Place a layer of gingerbread cubes on the bottom of a trifle dish. Top with 1/3 of the bourbon cream. Sprinkle some pecans and pomegranate arils. Repeat two more times, finishing with cream on top. Before serving, drizzle with caramel topping and garnish with the remaining pecans and pomegranate.