Preheat the oven to 350° F.
In a medium-sized bowl, combine cake mix, dry pudding mix, water, oil, eggs, lemon zest and lemon juice. Beat on medium – high speed until all ingredients are well blended. Use a spatula to mix the batter from the bottom of the bowl to the top.
Pour the batter into a 9-inch by 13-inch pan that has been sprayed with nonstick cooking spray and bake at 350°F for about 25-35 minutes until cake is set. Test cake by inserting a toothpick into the center. If the toothpick comes out clean, the cake is done. (I would check at 25 mins, especially if you're using a glass pan.)
While the cake is still warm, take the end of a wooden spoon or another round object and poke holes all over the top of your cake. Allow to cool for 20 minutes.
While the cake is cooling, dissolve gelatin in boiling water in a small bowl, stirring constantly.
Once gelatin is dissolved, pour mixture slowly over entire cake. Let the cake chill in the fridge for about 45 - 60 minutes.
Once cake has chilled, combine lemon juice and whipped topping. Spread evenly over the top of the cake. Add sliced strawberries and lemon zest over the whipped topping.
Chill until ready to serve and enjoy!