Preheat oven to 325°F (163ºC). 
Whisk together in a medium mixing bowl, flour (3 cups), baking powder (1/2 teaspoon), and salt (1/2 teaspoon); set aside.
 In the bowl of a stand-up mixer, beat butter (1 1/2 cups) on medium speed, until light and fluffy, 4 minutes.
 Gradually add sugar, beating until light and fluffy, about  4 minutes. Add sour cream and mix until combined.
 Add eggs, one at a time, beating until yolk disappears, after each addition. 
 Add flour mixture to batter, alternating with cream of coconut, beginning and ending with flour mixture. Stir in vanilla extract and coconut extract.
 Using a large rubber spatula, fold in shredded coconut.
 Grease and flour a 12-cup bundt pan. Dust with granulated sugar then sprinkle with toasted coconut (1 1/2 cup).
 Pour batter into prepared pan. Tap pan on the counter to remove any air bubbles.
 Bake for 45 minutes in the preheated oven. Cover with foil and continue to bake, about 45 minutes longer, or until a wooden skewer inserted into the center comes out with just a few moist crumbs. Cool in the pan on a wire rack for 1 hour. Remove from the pan and cool completely on a wire rack.