Preheat the oven to 350°F (175°C).
In a large mixing bowl, cream together the softened butter and granulated sugar until light and fluffy.
Add the eggs one at a time, mixing well after each addition.
Stir in the pineapple and vanilla extract.
In a separate bowl, whisk together the flour, baking powder, and salt.
Gradually add the dry ingredients to the wet mixture, mixing just until combined.
Pour the batter into a greased cake pan and smooth the top.
Bake for 30-35 minutes or until a toothpick inserted in the center comes out clean.
Allow the cake to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.
While the cake cools, prepare the cream cheese frosting by beating the softened cream cheese, powdered sugar, and milk until smooth.
Once the cake is cool, spread the cream cheese frosting evenly over the top.