Preheat Oven and Prepare Bundt Pan - Preheat the oven to 350 degrees Farenheit. Grease the bundt pan you are using with cooking spray.
Combine Cake Mix, Lemon Gelatin, Water, Vegetable Oil, and Eggs - In a large mixing bowl, add the yellow cake mix, lemon gelatin, water, vegetable oil, and eggs. Using an electric mixer, beat the lemon cake batter mixture on low speed for 30 seconds until combined. Scrape down the sides of the bowl with a rubber spatula and beat the cake batter for one more minute, increasing the speed to medium.
Bake the Cake - Pour the lemon cake batter into the bundt pan. Bake the lemon bundt cake for 35-40 minutes, until golden brown and a toothpick inserted into the middle comes out clean.
Allow the cake to cool in the bundt cake pan for 10 minutes before letting it cool on a wire rack. To remove the cake from the pan, run a knife around the edge to help loosen it, then invert it onto the wire rack.
Make the Glaze - In a medium bowl, add the powdered sugar, lemon juice, and lemon zest to make your fresh lemon glaze. Using a whisk, mix the glaze ingredients together until smooth.
If you are in a pinch, you can use lemon juice from a bottle. However, fresh lemon juice is the best choice when possible.
Decorate the Cake - Once the cake is completely cool, pour the glaze over the top. Cut the cake into slices, serve and enjoy.