Preheat your oven to 350°F and position a rack in the center. Grease a 9×13-inch pan or line it with parchment paper.
In a large bowl, whisk together the boxed cake mix, all-purpose flour, baking powder, and dry ingredients until uniform.
In another bowl, beat the butter mixture and cream cheese with a hand mixer until light and fluffy. Add eggs one at a time, whisking well after each. Stir in vanilla extract.
Combine cake mix mixture with the wet ingredients, alternating with crushed pineapple and pineapple juice. Mix until the batter looks smooth and evenly combined.
Pour the batter into the prepared pan, spreading it out evenly over the top.
Bake for 25–30 minutes or until a toothpick comes out clean when inserted in the center.
Remove the cake and let the cake cool in the pan for pan for 10 minutes. Then transfer to a wire rack to cool completely.
Once cool, frost with cream cheese frosting or spoon a sweet pineapple glaze over the top. Garnish with toasted coconut and chopped pecans.