Preheat oven to 350 degrees F (180 degrees C). Grease or spray a 10 cup capacity bunt pan, and set aside.
In a medium bowl, sift All-Purpose Flour (3 cup), Baking Powder (2 teaspoon), and Salt (1/2 teaspoon). Set aside.
In the bowl of a stand mixer fitted with the paddle attachment over medium-high speed, cream together Unsalted Butter (3 stick) and Granulated Sugar (3 cup) for 4-6 minutes. It should be fluffy and creamy. Add the Egg (5) one at a time, mixing well after each addition, make sure to scrape the bottom and sides of the bowl.
Add the juice and zest of a Lemon (1), the zest of a Lime (1), and Vanilla Extract (1 teaspoon). Mix until well mixed.
Add 1/3 of the flour mixture along with the Milk (1/3 cup) and mix to combine. Add half of the 7UP® (1 cup) and mix. Add another 1/3 of the flour and all the 7up and mix then all the rest of the flour and mix until well combined.
Pour batter in prepared bunt pan, spread the batter batter evenly. Bake for 1 hour or until a toothpick inserted comes out clean.