Preheat oven to 350°F (175°C) and grease a 9x13-inch pan.
Sift the flour and baking powder three times for extra fluffiness.
In a mixing bowl, beat butter and sugar until light and fluffy (about 5 minutes).
Add eggs one at a time, mixing well after each addition. Add vanilla.
Gradually mix in the flour mixture until just combined. Do not overmix.
Pour the batter into the greased pan and bake for 25-30 minutes, or until a toothpick comes out clean.
Let the cake cool completely, then poke holes all over the surface using a fork or skewer.
In a bowl, mix sweetened condensed milk, evaporated milk, and heavy cream.
Slowly pour the milk mixture over the cake, letting it absorb between pours. Refrigerate for at least 4 hours or overnight.
Whip the cream, sugar, and vanilla until stiff peaks form. Spread over chilled cake before serving.