Preheat oven to 325F degrees. Spray 10-inch bundt pan with nonstick cooking spray (that has flour in it) or grease and flour bundt pan.
In a medium bowl, combine all the cake ingredients (cake mix, pudding, 7up, eggs and oil).
Mix until thoroughly combined.
Pour batter into bundt pan.
Bake for about 35-45 minutes (until inserted toothpick or fork comes out clean). Allow to cool completely, then remove from bundt pan and place on a cake plate.
Start preparing icing. In a small bowl, combine sugar, lemon juice and lemon zest (if using).
Add milk in slowly until you've reached desired consistency. I personally like it a bit on the thicker side.
Allow it to sit for a bit to set up (it won't harden up fully like a frosting) then slice and serve.
Video
Notes
Please refer to my FAQ’s and ingredient list above for other substitutions or for the answers to the most common questions.