Stem and seed the ancho chiles . Toast them on a dry skillet over medium, pressing them flat against the hot surface for about 10 seconds with a metal spatula until they are aromatic and have lightened in color a little on the inside; flip and toast the other side. Place the chiles in a bowl, cover with hot water, weight with a plate to keep them submerged and let rehydrate 20 minutes. Drain and discard the water. Transfer the softened chiles to a blender or food processor and add 2/3 cup water. Process to a smooth puree. Scrape through a medium sieve to catch any skins or seeds. Measure out 1/4 to 1/3 cup, depending on how spicy you want the mousse and scrape it into a medium bowl. Transfer the remaining chile puree into a jar, seal with a lid and place it in the refrigerator. It’ll last for up to 3 months.
Using a vegetable peeler, shave some chocolate from the bar to use as a garnish (about 1/2 ounce), then chop the remaining (5 1/2 ounces) chocolate and scrape the chopped chocolate into the bowl with the ancho puree. Sift the cocoa into the bowl.
Soak the gelatin in cold water for a few minutes until it blooms (softens). (If you’re using powdered gelatin see the testing notes below.) Squeeze out the water from the gelatin sheets and discard the water. Heat the Kahlua in a small microwave safe bowl for about 30 seconds until it’s hot. Add the bloomed gelatin and stir until it’s completely dissolved, then add the vanilla and 1/4 teaspoon salt.
Measure 1/2 cup heavy cream into a small saucepan and bring to a brisk simmer. Pour the hot cream over the chocolate chile mixture and stir until all the chocolate has melted, then stir in the Kahlua/gelatin mixture.
Pour 1 1/2 cups heavy cream into a mixing bowl and whip to medium peaks. Scoop into the bowl with the chocolate base and gently fold to combine. Spoon into 4 decorative stemmed glasses. Place the glasses in the refrigerator to chill for 2 hours before serving. Cover the glasses with plastic wrap if you’re planning on leaving them in the refrigerator for more than 2 hours. Just before you’re ready to serve, whip the remaining 1/2 cup heavy cream and spoon a dollop on each serving. Sprinkle on the chocolate shavings, then it’s time to dig in.
Testing Notes: If you’re unable to get sheet gelatin, you can use powdered gelatin instead. In a small bowl, mix together the Kahlua and vanilla. Sprinkle 1 1/4 teaspoons of powdered gelatin and stir to combine. Let it sit for 10 minutes until the gelatin blooms and all the liquid has been absorbed. Heat the cream, but before you pour it over the chocolate chile mixture, stir in the gelatin and make sure that it completely dissolves before you add it to the chocolate. From that point, you’re back to following the original recipe.
Jill's Wine Recommendations: I suggest an LBV port. The Warre’s LBV brings out the fruitiness of the Ancho chile. If you like a drier style port, I suggest the Quinta do Noval LBV which brings out more of the dark chocolate flavor. It’s a great way to end a romantic Valentine’s meal.