Preheat the oven to 180°C (350°F). Grease and flour a round cake mold to prevent sticking.
Mix the dry ingredients: In a bowl, combine the flour, baking powder, and salt. Set aside.
Cream the butter and sugar: In another large bowl, beat the softened butter and sugar together until the mixture is light and fluffy.
Add the eggs: Incorporate the eggs one at a time into the butter mixture, making sure to beat well after each addition.
Blend in flavors: Mix in the sour cream, vanilla extract, and coconut extract. Stir until everything is well combined.
Combine dry and wet ingredients: Gradually add the flour mixture to the wet mixture, beating at low speed until everything is just combined. Fold in the grated coconut gently.
Bake the cake: Pour the batter into the prepared mold and bake for about 1 hour and 15 minutes, or until a toothpick inserted in the center comes out clean.
Cool the cake: Allow the cake to cool in the mold for around 10 minutes, then remove it and let it cool completely on a wire rack.
Prepare the glaze: Beat the softened butter until creamy. Gradually add powdered sugar and milk until you reach a smooth consistency. Stir in the vanilla and coconut extracts.
Finish the cake: Once the cake has cooled completely, drizzle the glaze on top and sprinkle with grated coconut for decoration.