Step 1: Prepare the Cake Layers : Preheat your oven to 350°F (175°C). Grease and line two 9-inch round cake pans with parchment paper. In a medium bowl, whisk together flour, baking powder, baking soda, and salt. In a large bowl, cream the butter and sugar together until light and fluffy (about 3–4 minutes). Add eggs one at a time, beating well after each addition. Stir in vanilla and coconut extracts. Alternate adding dry ingredients with coconut milk and buttermilk, starting and ending with flour. Mix until smooth and creamy. Divide batter evenly between pans and bake for 25–30 minutes, or until a toothpick comes out clean. Let cakes cool in pans for 10 minutes, then transfer to a wire rack to cool completely.

Step 2: Make the Coconut Cream Filling : In a saucepan, whisk together sugar, cornstarch, and egg yolks. Gradually whisk in milk and coconut milk until smooth. Cook over medium heat, whisking constantly, until the mixture thickens and comes to a gentle boil (about 7–9 minutes). Remove from heat, stir in butter, vanilla, and coconut extract. Fold in shredded coconut, cover with plastic wrap (touching the surface), and chill completely.

Step 3: Prepare the Fluffy White Frosting : In a small saucepan, combine sugar and water. Heat over medium heat without stirring until it reaches 240°F (soft-ball stage) on a candy thermometer. Meanwhile, beat egg whites, cream of tartar, and salt in a stand mixer until soft peaks form. Slowly drizzle the hot syrup into the egg whites while beating constantly on high speed. Continue beating until glossy and stiff peaks form (about 6–8 minutes). Beat in vanilla extract at the end.

Step 4: Assemble the Cake : Place one cake layer on a serving plate. Spread a generous amount of coconut cream filling over the top. Add the second cake layer on top and frost the entire cake with fluffy white frosting using an offset spatula. Gently press toasted coconut onto the sides and top of the cake. Chill the cake for at least 30 minutes before serving to set the layers.