Preheat your oven to 350°F (175°C) and grease a 9x13-inch baking pan.

In a large bowl, whisk together the cake mix, eggs, vegetable oil, and water.. Mix until smooth using a hand mixer or a whisk.

Transfer the batter into the prepared pan and smooth it out evenly.

Bake the cake in the preheated oven for 28–30 minutes, or until a toothpick inserted into the center comes out clean.

Allow the cake to cool in the pan for about 10 minutes before moving on to the next step.

While the cake is cooling, mix the lime filling: In a separate bowl, combine the sweetened condensed milk, lime juice, and lime zest. Stir until fully combined and smooth.

Once your cake has cooled slightly, poke holes in the cake with a fork or the end of a wooden spoon. Poke generously—about 20–30 holes—throughout the entire cake to allow the lime filling to soak in.

Pour the lime mixture over the cake, making sure it gets into the holes. Gently spread the mixture to cover the entire surface.

After pouring the lime filling over the cake, cover the cake with plastic wrap and refrigerate for at least 2 hours (or overnight for best results). This will help the cake soak in all those bright, zesty lime flavors and give it a perfect texture.

Once the cake is fully set, it’s time to make the creamy topping! In a large bowl, whip the heavy cream with powdered sugar and vanilla extract using a hand mixer or stand mixer until stiff peaks form.

Spread the whipped cream evenly over the cooled, lime-filled cake.

For an extra touch of flair, garnish with fresh lime slices, shredded coconut, or extra lime zest for texture and flavor.

Cut into squares and serve immediately, or store in the fridge until ready to enjoy!