Martha's Chocolate Truffles with a Kick

Put the cream and cardamom in a small saucepan. Warm the cream mixture over medium-high heat, stirring occasionally, until the cream begins to boil. Cover, remove from the heat, and let sit for 1 hour. Taste and let sit longer if you want a stronger flavor. Strain the cream and return to the saucepan, discarding the cardamom.

Grind 12 oz. of the chocolate in a food processor until it reaches the consistency of coarse meal, about 30 seconds. Bring the cream to a boil in a small saucepan over medium heat. Add the cream, chili powder and Kahlua to the food processor and process until smooth, about 10 seconds. Add the butter and process until smooth, about 10 seconds.

Transfer to an 8-inch square glass baking dish, cover tightly with plastic wrap, and refrigerate until firm, about two hours.

Using 2 teaspoons, scoop rounded, heaping teaspoonfuls of truffle mixture onto a large, parchment-lined baking sheet. When all of the truffles are scooped, use your palms to roll the truffles into smooth 1-inch balls (don't worry about making them perfect; slightly irregular truffles have an appealing homemade appearance). Transfer the truffles to the refrigerator and chill for at least 20 minutes.

Melt the remaining 8 oz. of chocolate in a medium heatproof bowl set in a small skillet of barely-simmering water, stirring occasionally until smooth. Transfer the bowl to a work surface.

Put the crushed toffee bars in a medium bowl.

Working in batches, use a fork to dip the truffles in the melted chocolate, then roll them in the crushed toffee bars until well-coated. Let the truffles cool for a minute or two in the bowl of crushed toffee bars, then return them to the parchment-lined baking sheet.

Let the truffles sit at room temperature for at least 15 minutes before serving. If not serving right away, store them in an airtight container for up to 5 days. Bring them to room temperature before serving.