Place 6 ounces chocolate in a heat-proof bowl. Heat 6 ounces cream in a saucepan just until boiling, about 3 minutes. Pour cream over chocolate; let stand for 1 minute; stir until well combined. Place over a bowl of ice water; stir until spreadable consistency. Use immediately.Advertisement
Repeat with remaining chocolate and cream, but do not place over ice water. While warm, pour over cake to glaze.