Grandma Helens Pistachio Cake

1 box white cake mix
2 packages pistachio pudding
5 eggs
1/2 cup water
1/2 cup vegetable oil
1/2 cup milk
1 1/2 tsp vanilla

Combine all ingredients in mixing bowl. Beat 5 minutes on high speed. Pour into greased and floured bundt pan. Bake 350 degrees for 65-70 minutes. Dust with confectioners sugar before serving.