Preheat your oven to 350 °F (176°C). Brush the pan with solid vegetable shortening and dust with flour or use baking spray with flour in it to grease the pan.
In a medium bowl, combine the flour, baking powder and salt. Set this aside.
2 1/4 cups (281 grams) white whole wheat flour, 2 1/4 teaspoons baking powder, 1/2 teaspoon salt
In a large bowl, mix together the sugar, melted coconut oil, eggs, coconut milk, coconut rum, vanilla and coconut extracts until well combined. Fold in the flour mixture, just until no more streaks of flour remain. Fold in the coconut flakes.
1 3/4 cups (350 grams) granulated sugar, 9 tablespoons (126 grams) coconut oil, 4 large eggs, 3/4 cup (177 ml) coconut milk, 1/2 cup (118 ml) coconut rum, 1/2 teaspoon vanilla extract, 2 teaspoons coconut extract, 2 cups (170 grams) coconut flakes
Pour the batter into the prepared Bundt pan and bake for 40-50 minutes, or until a toothpick inserted in the middle comes out clean. The cake will crack around the top - stick the toothpick into this area to test.
Let the cake cool in the pan for 10 minutes and then invert onto a wire rack. While the cake is cooling, prepare the coconut rum syrup. In a large saucepan over medium heat, heat the butter, water, sugar and salt until the sugar has dissolved, stirring occasionally. Take the saucepan off the heat and stir in the coconut rum (it'll bubble).
1/2 cup (112 grams) unsalted butter, 1/2 cup (120 ml) water, 1/2 cup (100 grams) granulated sugar, 1/4 teaspoon salt, 1/2 cup (118 ml) coconut rum
Wash and dry the Bundt pan and place the cake back into the pan. Poke holes into the cake (I used a meat thermometer to do this), about every 3/4" or so. If using the Crown Bundt, make sure to poke your holes at an angle instead of poking straight down. Pour the syrup slowly over the cake. It will look like WAY too much syrup but don't stop pouring! It will get absorbed. Let soak for 2 hours and then invert the cake back onto a serving platter. Cover and store at room temperature for up to 3 days. General tip: if you have issues with the syrup-drenched cake not coming out of its pan, place the Bundt pan in a large bowl or pot. Very carefully fill with very hot water, but make sure that no water gets in the pan. Or you can fill a pot with hot water and submerge 2/3 of the pan in the water and hold it there for 30 seconds. The heat and steam will help loosen the cake from the pan. If it doesn't plop right out, give the top of the pan a good whack.
Let the cake cool completely. Cover and store at room temperature for up to 3 days.