Preheat the oven to 350°F (175°C). Grease a 9x13-inch baking pan with non-stick spray.
In a medium bowl, whisk together flour, baking soda, baking powder, ginger, cinnamon, allspice, cloves, and salt. Set aside.
In a large mixing bowl, beat butter and brown sugar until creamy. Add the egg, molasses, and vanilla extract. Beat until smooth.
Gradually mix the dry ingredients into the wet mixture on low speed until just combined.
Stir in the hot water until the batter is smooth. Pour into the prepared pan.
Bake for 25–30 minutes, or until a toothpick inserted in the center comes out clean. Allow the cake to cool completely.
While cooling, whip the heavy cream, powdered sugar, and vanilla extract with an electric mixer until firm peaks form.
Slice the cake and serve with whipped cream and banana slices. Enjoy!