Key Lime Poke Cake

Preheat oven to 350 degrees F. Grease a 9x13-inch baking dish. Set aside.
In a large bowl, beat together the cake mix, water, vegetable oil, and eggs for 2 minutes. Pour into the greased pan. Bake for 22-28 minutes until a toothpick inserted into the center comes out clean.
While the cake is still warm, use the handle of a wooden spoon or a wooden skewer to poke holes all over the top of the cake.
In a medium bowl, add sweetened condensed milk, whipping cream, and lime zest. Whisk to combine. Add lime juice and whisk quickly. Before the mixture thickens, pour it over the cake and use a spoon to spread it to cover the cake completely. Refrigerate the cake for at least 1 hour or overnight.
When ready to serve, beat heavy whipping cream and vanilla extract in a small bowl until it starts to thicken. Add the powdered sugar and continue beating until stiff peaks form. Spread over the cold cake. Garnish with sliced limes or lime zest.