Preheat the oven to 350° F. Generously butter or spray a 9 by 13-inch baking pan with non-stick spray.
Make the brownie batter: Melt together the butter and chocolate in a medium-sized pot over low heat, stirring until smooth. Remove from the heat and stir in the cocoa powder, sugar, and salt, then blend in the vanilla. Beat in the eggs one at a time, stirring quickly so they don’t have a chance to cook at all before they are blended in. Blend in the flour.
Scrape about 3/4 of the thick batter into the prepared pan and smooth the top with a spatula. Set the pan and the remaining brownie batter (about one cup) aside.
Make the pumpkin cheesecake batter: In a large bowl bet the cream cheese with an electric mixer until smooth. Add the sugar, cinnamon, ginger, salt, and cloves and beat, scraping down the sides, until well combined. Beat in the eggs, one at a time, then beat in the pumpkin, cream and vanilla until smooth. Spread the pumpkin cheesecake batter over the brownie batter in the pan, then use a tablespoon to dollop remaining brownie batter over the top in spots. Use a dull knife to swirl the mixtures together on top, making sure to leave it very streaky, and not blend too much.
Bake for about 40 to 45 minutes, until a toothpick inserted into the middle of the brownies comes out clean.
Allow the brownies to cool completely in the pan set on a wire rack. Cut into 24 squares.