Preheat the oven to 350°F (175°C) and grease a 9x13-inch baking pan.
In a medium bowl, whisk together the flour, baking powder, and salt.
In a large bowl, beat the eggs and granulated sugar with an electric mixer until light and fluffy, about 5 minutes.
Add the milk and vanilla extract to the egg mixture and mix well. Gradually add the dry ingredients, stirring until smooth.
Pour the batter into the prepared pan and bake for 25-30 minutes, or until a toothpick comes out clean. Allow the cake to cool completely in the pan.
In a separate bowl, whisk together the evaporated milk, sweetened condensed milk, and whole milk.
Once the cake is cool, poke holes all over the surface using a fork. Slowly pour the milk mixture over the cake, letting it soak in completely.
Cover and refrigerate the cake for at least 2 hours or overnight for best results.
To prepare the topping, whip the heavy cream, powdered sugar, and vanilla extract until soft peaks form.
Spread the whipped cream over the chilled cake and serve. Enjoy your Tres Leches Cake!