Preheat your oven to 350°F (175°C).
In a mixing bowl, cream together the softened butter and sugar until light and fluffy.
Add the eggs one at a time, mixing well after each addition. Then mix in the vanilla extract.
In a separate bowl, combine the flour, baking powder, baking soda, and salt.
Gradually add the dry ingredients to the wet mixture, alternating with buttermilk. Start and end with the flour mixture.
Fold in the crushed pineapple gently until evenly distributed.
Scoop the batter into lined cupcake tins, filling each liner about 2/3 full.
Bake in the preheated oven for 18-20 minutes or until a toothpick inserted comes out clean.
Once baked, allow the cupcakes to cool in the pan for 5 minutes before transferring to a wire rack to cool completely.
While the cupcakes cool, prepare the frosting. Whip the heavy cream until stiff peaks form, then gradually add in the powdered sugar and crushed pineapple.
Once cupcakes are cool, pipe or spread the pineapple frosting generously on top.
Optionally, top the cupcakes with additional crushed pineapple or a maraschino cherry for decoration.