Preheat the oven to 325°F. Arrange an oven rack in the center of the oven. Thoroughly grease and lightly flour two 6-cup bundt pans.
In a medium-size mixing bowl, whisk together flour, baking powder, and salt. Set aside.
In a large mixing bowl, beat the butter and sugars together, on medium speed, until light and fluffy. Add the eggs, vanilla, and coconut extract beat until smooth. Add the milk, beat on low speed to combine. Add the flour mixture and beat just until combined. Stir in the coconut.
Pour the batter into the prepared pans. Bake for 50-55 minutes, until golden on top and light brown on the edges. A toothpick inserted should come out with moist crumbs. Cool in the pan on a wire rack for 15 minutes.
After 15 minutes, place the cooling rack on top of the cake, hold the sides firmly and invert the pan over the rack. The cake should drop smoothly out of the pan. Tap firmly on the pan with a wooden spoon, if necessary to free the cake from the pan. Let the cake cool completely before glazing.
To make the glaze, melt the butter in a small glass bowl. Add the powdered sugar, milk, and coconut extract. Whisk together until smooth. The glaze should pour off the spoon in a white stream. Add a teaspoon more milk to thin it, or 1-2 tablespoons more powdered sugar to thicken it, if necessary.
Drizzle the glaze over the cake. Sprinkle generously with coconut. Store at room temperature, loosely covered, preferably not airtight. This cake will keep nicely and stay very moist for 3-4 days.
Notes
You can also bake this cake in a 12-cup bundt pan for 60 - 65 minutes.