Heat the oven to 350°, and spray a 9x13-inch pan with cooking spray.
In a bowl, combine the flour, cinnamon, baking soda, ginger, cloves, nutmeg, allspice, and salt together.
In a separate bowl, beat the butter, sugar and brown sugar together until creamy. Add the molasses and eggs and beat to combine.
Add the flour and combine. Pour in the hot water and stir well.
Pour into the prepared pan and bake for 40 minutes, or until a toothpick comes out clean and the cake starts to pull from the sides.
While the cake is baking, make the caramel sauce. Add the brown sugar, butter, and whipping cream to a pan. Bring to a simmer and cook over medium low until the sauce begins to thicken. Stir in the vanilla. The sauce will continue to thicken as it cools.
Serve the cake with ice cream and caramel sauce.