Preheat your oven to 350 degrees F. Grease an 8-inch x 4-inch loaf pan, coat with non-stick spray, or line with parchment paper.
In a large bowl, whisk together sugar and butter until bright and fluffy. Add the 2 eggs, one egg at a time.
Mix flour with baking powder and salt together. Then add half of the dry ingredients along with the pineapple syrup to the egg mixture. Gently mix, then add the remaining flour along with the milk and stir once more. Then fold in the crushed pineapple until combined. I do this with a spoon or rubber spatula. DO NOT over mix the batter or your bread will be really dense.
Pour the batter into the prepared pan and bake on the middle rack for 45-55 minutes until set in the middle and browned. The bread is done when a toothpick inserted in the center comes out clean. If the top begins to get too brown, tent with aluminum foil.
Let the bread rest in the pan for around 10 minutes, then turn it out onto a wire rack to cool.
Whisk together powdered sugar, vanilla, and pineapple syrup to make the glaze. Then spread it evenly over the bread.
If you run out of pineapple syrup, you can use milk instead for the glaze.
To get a thin, shiny glaze, spread it when the bread is still warm. For a thicker, whiter glaze, wait until the bread has completely cooled down.