Boca Negra Chocolate Chipotle Cakes

Put oven rack in middle position and preheat oven to 325°F. Butter ramekins and dust with sugar, knocking out excess.

Toast chiles in a dry heavy skillet over moderate heat, turning, until fragrant, 1 to 2 minutes. Discard stems, seeds, and ribs, then soak chiles in hot water to cover until softened, about 30 minutes. Drain, reserving soaking liquid. Purée chiles in a mini food processor or a blender, adding 2 to 3 tablespoons soaking liquid as needed to form a paste. Force paste through a fine-mesh sieve into a bowl and discard solids. Set aside 1 1/2 tablespoons chile paste and freeze remainder for another use.

Bring juice and 1 cup sugar to a boil in a 1- to 1 1/2-quart saucepan, stirring until sugar is dissolved. Pour hot syrup over chocolate in a large bowl, stirring until chocolate is melted. Add butter and stir until melted.

Add eggs 1 at a time, whisking after each addition, then stir in chile paste, flour, and salt. Divide among ramekins and bake in a hot water bath, uncovered, until just firm and top is starting to crust, 50 to 60 minutes. Transfer ramekins with tongs to a work surface and let stand 2 minutes.

Unmold warm cakes directly onto dessert plates (they will be difficult to move once they adhere).

Cooks' notes:
• Cakes can be made and unmolded (while hot) up to 2 hours ahead and kept at room temperature, uncovered.
• If you have limited counter space and are baking cakes ahead, unmold cakes onto a baking sheet lined with a nonstick bakeware liner (such as Silpat) and transfer to dessert plates with a spatula before serving.