Preheat your oven to 350°F and grease a 9x13-inch baking dish or bundt pan.
In a large mixing bowl, combine the yellow cake mix, lemon gelatin, eggs, vegetable oil, and water.
Beat until the batter is smooth and well mixed.
Pour the batter into the prepared pan and spread it evenly.
Bake for 30 to 35 minutes, or until a toothpick inserted in the center comes out clean.
While the cake bakes, whisk together the powdered sugar, lemon juice, and water in a small bowl to make the glaze.
Let the cake cool for about 10 minutes after baking.
If making it as a poke-style cake, poke small holes across the top with a skewer or fork.
Pour the glaze over the warm cake so it soaks in.
Let the cake cool completely before slicing and serving.