Preheat your oven to 350°F (175°C) to ensure your cake bakes evenly.
Grease your 9x13 inch baking dish with butter and lightly dust it with flour.
In a mixing bowl, whisk together 1 ½ cups of cake flour, 1 teaspoon of baking powder, and ½ teaspoon of salt. Set aside.
Cream together 4 ounces of softened butter and 1 cup plus 1 tablespoon of sugar until light and fluffy (about 3-5 minutes).
Add the 5 large eggs one at a time, mixing well after each addition, then stir in 1 tablespoon of vanilla extract.
Gradually add the dry ingredients to the wet mixture, mixing until just combined.
Pour the batter into the prepared baking dish and spread it evenly. Bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean. Let the cake cool in the pan for about 10 minutes before transferring it to a cooling rack.
While the cake is cooling, combine 1 cup of evaporated milk, 1 cup of sweetened condensed milk, and 1 cup of whole milk in a mixing bowl and whisk until well blended.
Once the cake has cooled, poke holes all over the surface with a fork or skewer. Slowly pour the milk mixture over the cake, allowing it to soak in. Let it sit for at least 1 hour, or overnight in the fridge for best results.
In a mixing bowl, whip 1 cup of heavy cream with 2 tablespoons of sugar until soft peaks form.
Spread the whipped cream over the soaked cake and garnish with fresh fruit or a sprinkle of cinnamon if desired. Cut into squares and serve chilled.