How to Make It
Preheat oven to 350°F. Grease and flour a 14- to 16-cup Bundt pan. Beat butter in a stand mixer fitted with a paddle attachment on medium speed until creamy, about 2 minutes. Gradually add sugar, beating on medium speed until light and fluffy, 3 to 5 minutes. Add eggs, 1 at a time, beating until just blended after each addition. Add lemon zest, lemon juice, lime zest, and vanilla; beat on low speed until just blended, about 30 seconds. Add flour to butter mixture alternately with soft drink, beginning and ending with flour, beating until just blended after each addition.
Pour batter into prepared pan. Bake in preheated oven until a wooden pick inserted in center of cake comes out clean, 1 hour to 1 hour and 15 minutes, loosely tenting pan with aluminum foil after about 45 minutes to prevent excessive browning.
Cool cake in pan on a wire rack 10 minutes. Remove from pan. Transfer to wire rack, and let cool completely, 2 hours.
Spoon Lemon-Lime Cream Cheese Frosting into a piping bag or heavy-duty ziplock plastic bag. Cut a 1-inch hole in corner of bag, and pipe frosting in a roped pattern over top and sides of cake. Top cake with Sugared Lemon-Lime Zest.