1. Preheat the oven to 375 degrees, and butter an 8-inch round cake pan. Line the base of the pan with parchment, and butter the parchment too.Finely chop the chocolate and melt it gently with the butter in the microwave, stirring regularly until fully melted.
2. Add the sugar to the chocolate-butter mixture, stirring well, and set aside to cool for a few moments. Then add the eggs one by one, stirring well after each addition.
3. Add the cocoa, cinnamon, and cloves, and stir until incorporated.
4. Pour batter into the buttered cake pan and bake for approximately 25 minutes, or until the center of the cake looks set and the top is a bit crackly-looking and it only jiggles slightly, if at all.
5. Let the cake cool in its pan on a rack for 10 minutes, then carefully turn the cake out of the pan onto a place. Then invert it again, so that the crackly side is facing upward. Allow to cool completely. The cake will deflate slightly as it cools.
6. Serve in wedges at room temperature, dusted with confectioners sugar if you like, or topped with a dollop of whipped cream or vanilla creme fraiche.
7. Combine all ingredients in a small mixing bowl. Stir until fully incorporated. Taste and add more sugar, if desired.
8. Serve over chocolate cake or as a decadent topping for an ice cream sundae.