Preheat the oven to 350°F (175°C) and grease and flour a 9×13-inch baking pan for easy removal later.
In a large mixing bowl, combine the flour, granulated sugar, baking powder, baking soda, and salt, and mix well until the dry ingredients are fully integrated.
In another bowl, whisk together the pineapple juice, vegetable oil, eggs, and vanilla extract until well blended.
Gradually pour the wet ingredients into the dry ingredients, stirring gently until just combined; be careful not to overmix as a few lumps are perfectly fine.
Pour the batter into the greased baking pan and smooth the top with a spatula, then bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean.
While the cake cools, mix the powdered sugar and pineapple juice in a small bowl until smooth, adjusting the consistency by adding more juice or sugar as needed.
Once completely cooled, drizzle the sweet glaze over the cake, allowing it to soak in for an extra sweet touch.
Slice the cake and enjoy its tropical goodness.