Preheat oven to 325F degrees. Spray a 10-inch bundt pan really well with nonstick cooking spray (I like the kind with flour in it, like Baker's Joy).
In a medium bowl, combine all the cake ingredients: cake mix, pudding, 7-Up, eggs and oil. Mix until thoroughly combined.
Pour batter into prepared bundt pan.
Bake for about 45-55 minutes (until inserted toothpick comes out clean)
Once it's finished baking, while still in the pan, poke holes all over the cake using a wooden skewer and then pour reserved cherry juice into the cake. Allow the cake to cool completely.
Once the cake is cooled completely, carefully remove from the bundt pan.
To prepare icing: In a bowl, whisk together powdered sugar with lemon extract.
Whisk in milk slowly until you've reached the desired consistency.
Pour icing over cake and top with a few maraschino cherries.
Video
Notes
I prefer the icing to be thicker so I use less milk. I want it to be more like an icing and less like a glaze. However, this is easily customizable to your preferences.
Lemon instant pudding can be used instead of vanilla.
The video above has a typo. It should say maraschino cherry juice and not "Jell-O Mix"