Preheat the oven to 350°F (175°C). Grease and flour a 9×13-inch baking pan.
In a large mixing bowl, combine the lemon cake mix, water, vegetable oil, eggs, 2 tablespoons fresh lemon juice, and lemon zest.
Using an electric mixer, beat the mixture on medium speed for 2 minutes until smooth.
Pour the batter evenly into the prepared baking pan.
Bake in the preheated oven for 28 to 32 minutes, or until a toothpick inserted into the center comes out clean.
Remove the cake from the oven and allow it to cool in the pan for 10 minutes.
While the cake is cooling, prepare the lemon glaze by mixing the powdered sugar and 2 tablespoons fresh lemon juice in a small bowl until smooth.
After the cake has cooled for 10 minutes, drizzle the lemon glaze evenly over the top.
Allow the cake to cool completely before slicing and serving.