Spicy Mousse

Toast chiles in a medium dry saucepan over medium heat until fragrant and lightly browned, tossing often, about two minutes. Remove from pot and let sit until cool enough to handle. Crush chiles and return to pot with cream, vanilla, and cinnamon sticks and bring to a boil. Reduce to a simmer and cook 5 minutes. Remove from heat and let sit until cream has been infused with flavors, 15-20 minutes. Strain into a medium bowl set over ice and stir until mixture is cold. Whip just until very soft peaks form, watching constantly (cream will overbeat and curdle rapidly). Beat in powdered sugar and chill.

Melt chocolate in large heatproof bowl set over a saucepan of simmering water, stirring with a heatproof spatula just until smooth, about 5 minutes. Remove from heat and stir in butter pieces until melted. Stir in egg yolks one at a time until fully incorporated (mixture will look slightly grainy but will smooth out eventually). Set aside.

Beat egg whites until foamy and slowly add sugar, beating constantly, until soft peaks form. Do not overbeat. Gently fold egg white mixture into chocolate mixture in two additions. Gently fold in whipped cream mixture.

Spoon mousse into individual serving glasses, cover with plastic wrap, and chill until set, at least 2 hours and up to overnight.

Let mousse sit at room temperature before serving, 25-30 minutes. Serve mousse with softly whipped cream and more crushed chile.

Mousse can be made 1 day ahead.