In a large bowl, combine cake mix, eggs, sour cream, coffee liqueur, hazelnut liqueur and oil. Beat until very smooth. Stir in chocolate chips.
Pour batter into the greased and floured pans of you choice, and bake as directed on the cake box or until a knife inserted into the middle comes out clean. Wait until it's completely cool to frost.
For the frosting: Cream the butter. Add 1/2 of the icing sugar, blend well. Add the cocoa and vanilla, and start pouring the Irish cream over the icing while your beaters beat in the rest of the sugar. Keep adding Irish cream until you have wonderfully creamy icing.
Frost the cake (I like to press chopped nuts into the fresh icing). It's best served after a day or two, but even better to make it up to 6 months ahead of your special event, freeze it, and simply bring to room temperature. What a kick !