Preheat your oven to 350°F (175°C) and lightly grease and flour a 9×13 inch baking pan.
In a medium bowl, whisk together the all-purpose flour, baking powder, and salt.
In a large mixing bowl, beat the eggs and granulated sugar together on high speed for about 5-7 minutes.
Reduce the mixer speed to low and gently mix in the milk and vanilla extract.
Gradually add the dry ingredient mixture to the wet ingredients, mixing on low speed until just combined.
Pour the batter into the prepared baking pan and spread it evenly. Bake for 25-30 minutes.
Remove the cake from the oven and let it cool in the pan for about 15-20 minutes.
Using a fork or skewer, poke holes all over the top of the cake.
In a large bowl, combine the sweetened condensed milk, evaporated milk, full-fat coconut milk, pineapple juice, heavy cream, and non-alcoholic rum extract.
Slowly pour the Pina Colada milk mixture over the poked cake.
Cover the pan tightly with plastic wrap and refrigerate for at least 4 hours.
Before serving, prepare the whipped cream topping by combining heavy whipping cream, powdered sugar, and your chosen extract.
Spread the whipped cream evenly over the top of the cake.
Slice into squares and serve immediately.
Notes
For optimal flavor, let the cake soak overnight in the fridge. Use room temperature ingredients for a smoother batter.