Preheat oven to 375°F
Line a 12-cup regular muffin pan with paper liners or grease with nonstick cooking spray.
Crumb Topping
In a small bowl, combine flour, coconut, sugar and macadamia nuts. Whisk together until well-blended.
Using a fork or clean fingers, work in the butter until evenly combined and mixture resembles coarse crumbs and starts to come together.
Muffins
In a large bowl, combine flour, sugar, baking powder and salt. Whisk together until well-blended.
Stir in coconut.
In a medium bowl, whisk eggs until lightly beaten.
Gradually whisk in oil until well-blended.
Stir in pineapple juice.
Add egg mixture to flour mixture. Stir just until combined.
Fold in crushed pineapple.
Spoon batter into prepared muffin pan, filling cups 2/3 full.
Crumble topping over top of batter.
Bake for 20 to 22 minutes, or until a wooden pick inserted into center comes out clean.
Let cool in pan on a wire rack for 5 minutes.
Remove from pan and transfer to a wire rack to cool.