Preheat the oven to 350°F (175°C). Grease and flour a 9x13 inch cake pan.

In a mixing bowl, cream together the softened butter and granulated sugar until light and fluffy.

Add the eggs one at a time, beating well after each addition. Mix in the buttermilk and vanilla extract.

In another bowl, combine the flour, baking powder, and salt. Gradually add to the creamed mixture, mixing until just combined.

Fold in the crushed pineapple and shredded coconut until evenly distributed.

Pour the batter into the prepared cake pan and smooth the top.

Bake for 30 minutes or until a toothpick inserted into 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.

In a mixing bowl, beat the softened cream cheese and butter until smooth and creamy.

Gradually add the powdered sugar, mixing until fully incorporated.

Stir in the vanilla extract until well combined.

Once the cake is completely cooled, spread the frosting evenly over the top of the cake.

Sprinkle the additional shredded coconut on top of the frosting.