Preheat the oven to 350°F (175°C) and grease two 6-inch cake pans.

In a bowl, whisk together the flour, baking soda, baking powder, salt, ginger, cinnamon, and nutmeg.

In another bowl, cream together the butter and sugar until fluffy.

Add eggs one at a time, then stir in vanilla extract and orange zest.

Alternate adding the dry ingredients and buttermilk to the butter mixture, mixing until just combined.

Divide the batter between the prepared pans and bake for 25-30 minutes or until a toothpick inserted into the center comes out clean.

Let the cakes cool in the pans for 10 minutes, then transfer to wire racks to cool completely.

In a separate bowl, whip the heavy cream until stiff peaks form.

Gently fold in the gingerbread pudding to create a mousse.

Once the cakes are cool, layer them with the gingerbread mousse, spreading it evenly between the layers and on top of the cake.

Garnish with orange zest, if desired, and serve.