Preheat oven to 350°F. Line both loaf pans with parchment paper.
In a large bowl combine the cake mix, pistachio pudding mix, eggs, oil, water, and sour cream until blended.
Pour batter into parchment-lined loaf pans.
Bake for 45-50 minutes (might be slightly longer depending on oven style), or until a toothpick inserted into center comes out clean after being inserted into both loaf pans.
Allow loaves to cool in loaf pan 10 minutes before lifting out by parchment paper. Cool for 30 minutes before icing.
In a small bowl, whisk together the icing ingredients until thick and smooth.
Drizzle icing over the tops of the loaves and allow the icing to set for 10 minutes before slicing. Enjoy
Notes
Nutritional values may vary and are meant to be a guide.