Preheat oven to 350F. Butter and flour a bundt pan. Set aside.
In a small sauce pan on medium heat add drained mango, sugar, and 2 tablespoons rum. Cook until a thick syrup forms. Set aside.
Sift flour, baking powder and corn starch together.
In a stand mixer fitted with a bowl and a paddle attachment mix butter and sugar until fluffy. Add in eggs one at a time until fully incorporated.
Slowly drizzle in coconut milk, whipping cream, and vanilla. Mix until fluffy.
Pour 2/3 of batter into bundt pan. Top with mango, then cover with remaining batter. Bake for 40 minutes or until a toothpick inserted into the center emerges clean. Remove cake from oven and cool completely.
In a small bowl combine 2 tablespoons rum with powdered sugar until glaze forms. Pour glaze over bundt and sprinkle with coconut shavings.