To make the cake:

1. Preheat the oven to 350°F. Lightly grease three 8" round pans, and dust them with cocoa powder.
2. In a small saucepan set over low heat, bring the milk and ancho chili to a low simmer for 5 minutes. Remove them from the heat and set aside to cool completely. When cool, discard the chili.
3. In a large mixing bowl, whisk together the flour, baking powder, baking soda, salt, cocoa, hot chocolate mix, cinnamon, chili powder, and sugar. Add the butter and mix at low speed for 1 minute. With the mixer running, add the oil and continue to mix until the mixture looks like sand.
4. Add the vanilla and water to the chili-infused milk, and slowly add to the bowl with the mixer running. Mix for 1 minute on low speed, stop and scrape the sides and bottom of the bowl, then add the eggs one at a time, mixing well after each egg.
5. Divide the batter among the prepared pans. Bake for 22 to 24 minutes, or until the top springs back when touched in the center, and the cake just begins to pull away from the edge of the pan. Remove the layers from the oven, and place on a rack to cool completely. Once cool, turn the layers out of their pans.

To make the frosting:

6. In a double boiler over simmering water, combine the sugar and egg whites, whisking to combine. Stir until the sugar is completely dissolved, about 3 minutes. Transfer the mixture to the bowl of a stand mixer fitted with a whisk.
7. Whip at low speed for 1 minute. Add the cream of tartar, corn syrup, vanilla, and salt, and whip for 1 minute more. Increase the speed to medium and whip for 2 minutes, then increase speed to high and whip until very stiff peaks form, about 5 to 7 minutes more. Scrape the bottom of the bowl, whip for another 30 seconds, and set aside.

To make the ganache:

8. In a small saucepan set over medium heat, bring the cream and spices to a low simmer. Remove from the heat and add the chocolate chips. Whisk to combine until a smooth and shiny ganache forms. Let cool a few minutes before using.

To assemble the cake:

9. Place a layer on a serving plate. Pipe a thick ring of frosting on top, about half an inch from the edge of the cake. Fill the ring with more frosting. Gently place a second layer of cake on top and repeat the frosting steps. Place the final layer on top and frost the entire cake. Using a lightly greased offset spatula or the back of a spoon, carefully smooth the frosting on top of the cake.
10. When the ganache has cooled slightly, use a spoon to drizzle it down the sides of the cake. Spoon more ganache on top of the cake and smooth to make an even layer. Before the ganache sets, carefully pile marshmallows on top. Let the cake sit at least 30 minutes before slicing.