In a small saucepan over medium-high heat, heat cream until just boiling. Remove from heat.
Place 8 ounces of chocolate in a medium bowl, and pour hot cream over it. Let sit for 2 to 3 minutes. Stir cream and chocolate together until blended—the ganache will be the consistency of thick pudding. Set aside, and let come to room temperature.
When ganache is room temperature, stir in cheese. Pour into a baking dish, and cover with plastic wrap, pressing wrap onto ganache’s surface (make sure the plastic is directly on top of the ganache, or condensation will ruin the texture). Refrigerate for 1 to 2 hours, until firm enough to scoop.
Melt remaining chocolate in a double boiler. Remove from heat, and let come to room temperature.
Use a small melon baller to measure out a truffle, then use your hands to roll it into a ball. Place a dab of melted chocolate in your palm, then roll the truffle in it to coat. Roll truffle in cocoa powder until coated, and transfer to a parchment-lined tray. Continue with the rest of the ganache. Enjoy immediately or refrigerate in a tightly covered container for up to 3 days.