Preheat your oven to 350°F (175°C). Grease and flour a 9x13-inch glass baking dish.
Prepare the Cake Batter:
In a medium bowl, whisk together flour, baking powder, and salt. Set aside.
In a separate large bowl, beat the eggs and sugar with a hand mixer or stand mixer on medium-high speed until pale and fluffy, about 5 minutes.
Add the vanilla extract and lemon zest to the egg mixture.
Gradually fold in the dry ingredients, mixing gently until just combined.
Pour in the milk and continue mixing until the batter is smooth.
Bake the Cake:
Pour the cake batter into the prepared dish and bake for 30-35 minutes or until a toothpick inserted into the center comes out clean.
Remove from the oven and allow the cake to cool in the dish for about 10 minutes. Then, use a fork or skewer to poke holes all over the cake to allow the tres leches mixture to soak in.
Make the Tres Leches Mixture:
In a medium bowl, combine the evaporated milk, sweetened condensed milk, and heavy cream.
Pour this mixture evenly over the cooled cake, ensuring the entire surface is soaked. Let the cake absorb the mixture for about 1 hour in the fridge.
Make the Whipped Cream Topping:
In a chilled bowl, beat the heavy whipping cream with a hand mixer until soft peaks form. Gradually add the powdered sugar and vanilla extract, and continue beating until stiff peaks form.
Assemble and Garnish:
Spread the whipped cream evenly over the cake.
Garnish with lemon slices and a sprinkle of lemon zest for a fresh, citrusy finish.Slice and serve chilled. Enjoy the creamy, lemony goodness!