Preheat oven to 350˚F. Grease a 9 or 10-inch Bundt pan.

Toast the shredded coconut, stirring frequently, in a dry skillet over medium heat 1-2 minutes, until golden brown. Transfer to a dish and set aside.

Sift the flour, baking powder, and salt together in a large mixing bowl.

Heat the coconut milk in a small saucepan over medium heat. Add the butter and heat through until melted, stirring occasionally. Set aside.

Place the eggs, granulated sugar, minced kumquats, the tablespoon of orange juice, the tablespoon of lemon juice, and orange and lemon zests in the bowl of a stand mixer, or in a large mixing bowl. Mix with the mixer or hand-mixer at medium speed for 3-4 minutes, until very thick and almost doubled in volume. Mix in the vanilla, and then reduce speed to low and mix in the flour mixture, scraping down the sides as necessary. Still on low speed, add 1 cup of the toasted coconut, then in a slow stream pour in the coconut mixture. Use a rubber spatula to give the batter a final mix, then pour the batter into the prepared Bundt pan. Give the pan a shake to level the batter.

Bake in the center of the oven for 50-55 minutes, until a tester comes out clean. Transfer to a wire rack and allow to cool in the pan for 10 minutes. Invert the pan onto the wire rack and tap around the pan to release the cake. Set aside to cool.

In a small bowl, combine the confectioners' sugar with 1 teaspoon of orange juice and 1 teaspoon of lemon juice. Whisk in the 1/4 teaspoon of milk, and continue whisking until the icing is smooth. If the icing seems thick, add a few more drops of milk. It should be thin, but thick enough to cling to the back of a spoon. Drizzle the icing over the cake, then sprinkle with the remaining toasted coconut. Arrange the sliced kumquats on top. Allow the cake to rest at least 15 minutes before serving.