1. Preheat the oven to 375F and put one rack in the middle of the oven.

2. Butter all six cups of a popover pan (even if it’s nonstick); set aside.

3. Place the remaining butter, chocolate and orange zest in a small saucepan. Cook over very low heat, stirring constantly.

4. When the chocolate is almost entirely melted, remove from heat and let the chocolate mixture sit for a few minutes. Stir until smooth, and transfer to a mixing bowl.

5. Add the white and brown sugars, chili powder and cinnamon, and whisk until smooth. Whisk in the eggs one at a time, until the mixture is well combined.

6. Sift the cocoa powder and flour over the batter and carefully whisk it in.

7. When all the dry ingredients have been incorporated, divide the batter between the six popover cups.

8. Bake the cakes for 20 minutes, or until the tops begin to crack. Place the popover pan on a cooling rack.

9. When the pan is cool enough to touch, invert the cakes onto the cooling rack (place the rack on top of the popover pan, invert both, and tap the cakes gently out of their pans). Let the cakes cool to room temperature. At this point, the cakes can be wrapped and left overnight, if necessary. Make the ganache just before frosting cakes.

10. Before frosting, place the cooling rack over a baking sheet (to catch the dripping chocolate.) Using a flat spatula or a small knife, spread the ganache over the tops and sides of the cakes.

11. Allow the ganache to dry, then sprinkle with cinnamon or cocoa powder.