1. Start by preheating your oven to 350 degrees Fahrenheit (175 degrees Celsius) and prepare a 9×13 inch cake pan using non-stick spray.
2. In a large bowl, combine the dry cake mix, instant lemon pudding mix, lemon juice, eggs, and melted butter. Use a stand mixer or a hand mixer to mix the ingredients until they are fully combined.
3. Pour the batter into the prepared cake pan, smoothing it out with a spatula. The batter will be thick and fluffy, so make sure it’s evenly spread out.
4. Bake for 20 minutes and check for doneness using a toothpick. If it comes out clean, you’re ready to go.
5. Once fully baked, remove the cake from the oven and let it cool in the pan for a few minutes before transferring it to a wire rack.
6. While the cake cools, prepare the glaze by mixing the powdered sugar, lemon zest, and lemon juice.
7. Once the cake has cooled completely, pour the glaze over the cake in the pan or remove it and place it on a serving tray.
8. Garnish with fresh lemon slices if desired and serve.
