Creme de Menthe Bundt Cake

1 (18.25 ounce) box white cake mix
1 small box instant pistachio pudding
4 eggs
1/2 cup vegetable oil
1 cup water
2 tablespoons cr?me de menthe (liqueur)
6 drops green food coloring
1/2 cup Hershey's chocolate syrup

Drizzle Icing
1 cup granulated sugar
4 tablespoons margarine
4 tablespoons milk
1 (6 ounce) package chocolate chips

Cake: Mix all together, except the Hershey's syrup, for about 4 minutes at medium speed. Pour 2/3 of batter into a well greased Bundt pan. To the remaining batter, add Hershey's syrup and mix well. Pour this over the rest of batter in Bundt pan. Do not mix it in. It will bake in by itself. Bake at 350 degrees F for 45 minutes. Cool in pan for 15 minutes, then turn out onto serving plate.

Frosting: Mix all ingredients except chocolate chips in a saucepan over low heat for 1 minute. Remove pan from heat and add chocolate chips. Stir until chips melt, then drizzle over the warm cake.