Preheat oven to 350 degrees and grease a 9×13 brownie pan. Cream together butter and sugar with electric mixer. Add in egg and molasses. In a separate bowl, combine flour, spices, and salt. Slowly add to creamed butter and sugar until combined.
Add water and beat for 30 seconds or until combined.
Pour into pan and bake 30-45 minutes or until toothpick inserted comes out clean and cake springs away from edges of pan. Once cooled, cut into small chopped squares.
For the Cinnamon Ginger Buttercream:
In the bowl of an electric mixer, cream butter until thick and fluffy. Add in powdered sugar 1 cup at a time. Mix well for 2 minutes. Add spices and heavy cream. Beat for 2 minutes or until fluffy. If too thick, add in more heavy cream (or milk).
For the Hazelnut Crunch topping:
In a saucepan on medium heat, combine all ingredients and stir until toasted and combined. Spread out on a cookie sheet until cooled. Crumble to topping!
Build trifles by layering gingerbread cake, cinnamon ginger buttercream (I used a fluted piping tip) and hazelnut crunch topping! You can also garnish with a gingerbread cookie! Enjoy!