Preheat the oven to 350°F. In a medium bowl, cream the butter for about 2 minutes with an electric mixer. Add the brown and granulated sugars and continue to cream until light and fluffy.
Add in one egg at a time, beating only until incorporated. Stir in the vanilla and crushed pineapple (along with the juices!) until fully combined.
In a separate bowl, whisk together the flour, salt and baking powder. Slowly add the flour mixture into the pineapple mixture and beat until incorporated. Do not over stir at this point. Spoon mixture into a muffin pan lined with cupcake liners about ⅓ of the way. Add a maraschino cherry in the center and then spoon the rest of the batter over top to fill the cupcake liners to about ⅔ of the way. If you don't want to add cherries, just fill about ⅔ of the way.
Bake the cupcakes 18-20 minutes or until a toothpick comes up clean. Remove from the oven. Allow to cool for several minutes in the muffin tin and then remove and cool on a cooling rack the rest of the way.
Make the Frosting: Cream butter in a medium mixing bowl using an electric mixer for about 2-3 minutes or until smooth and creamy. Add the powdered sugar one cup at a time. You can reserve the last ½ cup for the end if you feel it needs to be added.
Once the powdered sugar is mixed in, add the vanilla and then the cherry juice, starting 1 tablespoon at a time until you reach the desired consistency. For a darker pink frosting, add a drop or two of red food coloring.
When cupcakes are completely cooled, spread the frosting or pipe it on top, whatever you desire! Store the cupcakes for about 3 days at room temperature, tightly sealed or about a week in the refrigerator.