Preheat the oven to 400. Prep a muffin tin with muffin liners.
In a large mixing bowl, stir together the flour, baking powder, sugar, and salt.
In a 2 cup measuring cup, measure out the milk. Add the eggs and vanilla and lightly beat. This can be refrigerated and added to the dry ingredients right before baking.
Pour wet mixture into dry mixture.
Add pineapple and coconut and stir to combine.
Spoon batter into prepared muffin tin. Fill 3/4 full.
Bake for 18 to 20 minutes. Allow to cool slightly before serving.