Preheat oven to 350°.

Combine cake mix, pudding, sour cream, oil, water, and eggs in electric mixer with paddle attachment. Beat together on medium for 5 minutes until fluffy and thoroughly combined.

Stir in chocolate chips.

Pour into cake pans. Depending on size, bake for 25 minutes (for 6 inch cake) or until toothpick inserted comes out clean (you may have some chocolate on toothpick from the chips). Increase baking time for larger cake.

NOTE: If you want a stronger Jack Daniels flavor, you can add 1/4 cup to the cake batter as well as the fudge icing. Or add more to the fudge icing (add additional chocolate chips too so the icing doesn't thin out too much).

Let cake cool.

In a medium saucepan, combine butter, sugar, and evaporated milk.

Stir together until rolling boil and time for 1 minute, stirring constantly.

Remove from heat and add in chocolate chips and Jack Daniels.

Immediately pour over cake (will set up quickly).