For the Cupcakes:
Preheat the Oven:
Preheat your oven to 350°F (175°C) and line a cupcake tin with paper liners.
Mix the Dry Ingredients:
In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside.
Cream the Butter and Sugar:
In a separate large mixing bowl, beat the softened butter and sugar together until light and fluffy, about 2-3 minutes.
Add the Eggs and Wet Ingredients:
Add the eggs one at a time, beating well after each addition. Stir in the sour cream (or Greek yogurt), vanilla extract, pineapple juice, and drained crushed pineapple. Mix until combined.
Combine Wet and Dry Ingredients:
Gradually add the dry ingredients to the wet mixture, mixing until just combined. Do not overmix.
Fill the Cupcake Liners:
Divide the batter evenly among the cupcake liners, filling each about 2/3 full.
Bake:
Bake in the preheated oven for 18-20 minutes or until a toothpick inserted into the center comes out clean. Allow the cupcakes to cool completely on a wire rack before frosting.
For the Pineapple Frosting:
Make the Frosting:
Beat the softened butter until creamy, about 2 minutes. Add the powdered sugar, 1 tablespoon of pineapple juice, and vanilla extract. Continue beating until smooth and fluffy.
Add Pineapple:
Stir in the well-drained crushed pineapple. If the frosting is too thick, add a little more pineapple juice until it reaches your desired consistency.
Frost the Cupcakes:
Once the cupcakes are completely cool, use a piping bag or a spatula to frost each cupcake generously with the pineapple frosting.
Serve:
Serve immediately or refrigerate the frosted cupcakes until ready to enjoy. Garnish with small pineapple chunks or a sprinkle of shredded coconut for an extra tropical touch if desired.