Preheat oven to 350F and grease a 10 or 12 cup Bundt pan with cooking spray.
In a medium bowl, whisk together flour, cinnamon, baking soda, and salt.
In the bowl of an electric mixer, beat sugar, oil, and vanilla until combined.
Add eggs one at a time, fully incorporating after each addition. Beat till pale and fluffy (approx. 3-4 mins).
Add banana, pineapple, coconut, and macadamia nuts and mix until combined.
Add flour mixture and beat until just combined.
Pour into prepared Bundt pan and smooth the top with a spatula.
Rap Bundt pan on counter a couple of times to release air bubbles and fill nooks and crannies.
Bake until a cake tester comes out mostly clean (approx. 60-70mins).
Cool on a wire rack for 10mins.
Rap pan against counter to loosen the cake and turn out onto wire rack.
Cool completely before glazing.
Glaze:
Combine sugar and pineapple juice in a small measuring cup. Whisk with a fork until combined and lumps are gone. Add more juice as needed until desired consistency is reached.
Pour over cooled Bundt Cake.
Notes
* I freeze my over-ripe bananas and thaw them on the counter for an hour before using.