Prepare cake mix according to package directions. For a 3-layer cake, divide batter among three 9-inch round pans and bake as directed. Set aside to cool. For 4 layers, bake two 9-inch rounds, cool, and then cut each in half horizontally.
Prepare the mint mousse by mixing ½ package of gelatin with boiling water. Let set in the refrigerator. Once set, place in cold water to soften gelatin enough to loosen it from the pan. Place softened gelatin into a double boiler and melt.
In a separate double boiler, melt the chocolate, being careful not to burn it. Add melted chocolate to gelatin and mix well.
Whip egg yolks by hand in a small bowl to soft foamy peaks. Mean while, bring honey to a boil. Pour hot honey onto the yolk,s stirring constantly. Folk the melted chocolate into the yolk mixture. Heat the milk in a small saucepan. Stir the milk into the chocolate mixture.
In a large bowl, whip the cream to soft peaks and fold into the chocolate mixture. Add mint extract and green food coloring. Alternate cake layers with mint mousse in between each one.
Prepare the dark chocolate mousse by chopping chocolate into chunks and carefully melt in a double boiler or in the microwave. In a separate bowl, whip yolks to soft peaks. In a small saucepan, bring honey to a boil. While the honey is still hot, pour it into the yolks, stirring constantly, and whip until thick. Fold warm chocolate into yolk mixture. In a medium bowl, whip cream to soft peaks and fold into chocolate mixture. Cover the top and around the edges with dark chocolate mousse. Place in the refrigerator to set.
Prepare the Ganache by scalding cream in a small saucepan. Chop chocolate into pieces. Remove cream from heat and add chocolate. Stir until chocolate is completely melted. Pour evenly over the top of the dark chocolate mousse. Garnish with chocolate mint truffles or berries.