Preheat the oven to 350F degrees. Prepare a bundt pan by greasing it well with non-stick baking spray (or easy release baking spray which contains flour).
In a large mixing bowl, use an electric mixer on low speed to combine cake mix, ½ cup melted butter, and pineapple juice, mixing just until smooth.
Add the eggs and crushed pineapple (with the juice) and mix with the electric mixer on medium to high speed until well combined.
Pour the cake batter into the prepared bundt pan.
Bake the cake at 350F for 35-40 minutes until a toothpick placed into the cake comes out clean.
While the cake is baking, combine ¾ cup pineapple juice, ½ cup of the powdered sugar, and the ¼ cup butter in a medium saucepan and heat over medium heat, stirring often, until the glaze begins to simmer. Remove the glaze from the heat.
When the cake is fully baked, remove it from the oven and poke holes all over the cake in the pan to allow the glaze to soak into the cake. Pour 1/3 of the glaze over the cake in the pan. Set the cake aside to cool in the pan for 15 minutes.
Invert the pan onto a large plate or cake pedestal. Lift the pan away from the cake.
Whisk the remaining 1 ½ cups of powdered sugar into the glaze, then brush it over the whole cake.
Slice the cake and serve at room temperature.