Preheat the oven to 325 degrees F.
Butter a 12 cup bundt pan and dust it with granulated sugar. Set aside until needed.
Add the all-purpose flour, baking powder, and table salt to a large bowl. Whisk to combine and set aside until needed.
Add the coconut milk, buttermilk, and coconut extract to a small bowl. Whisk to combine and set aside until needed.
Add the unsalted butter and granulated sugar to the bowl of a stand mixer fitted with the paddle attachment. Beat on medium speed until light and fluffy (2 to 3 minutes).
Chop the white chocolate into small pieces. Place it in a microwave-safe bowl, and microwave on medium power for 20-30 seconds.
Stir and microwave again in 15-second bursts until melted and smooth, stirring after each interval.
Add the melted white chocolate to creamed butter and mix to combine.
Add the eggs and egg white one at a time to the mixture, scrapping the sides and bottom of the bowl in between each addition.
After all the eggs and egg whites have been added, beat at medium-high speed for about 2 minutes or until the mixture gets smooth and creamy and increases slightly in volume.
With the mixer on low speed, add one-third of the dry ingredients, followed by one-half of the wet ingredients. Repeat the process until finished, ending with the final third of the dry ingredients. Scrape the sides and bottom of the bowl between each addition.
Pour the batter into the prepared bundt pan.
Sprinkle the toasted coconut over the top of the cake, and then cover the coconut with the toffee bits.
Place the pan on the center rack of the preheated oven and bake for 50 to 55 minutes, or until a toothpick inserted in the center of the cake comes out clean with a few moist crumbs on it.
Place the bundt pan on a cooling rack for about an hour to cool to room temperature.
Invert the cake on a cake stand.