Preheat oven to 350°F (175°C). Grease and flour three 8-inch round cake pans, or line with parchment paper.

In a medium bowl, whisk together flour, baking powder, baking soda, and salt. Set aside.

In a large mixing bowl, cream together softened butter and granulated sugar with an electric mixer until light and fluffy (about 3-5 minutes).

Beat in eggs one at a time, incorporating each egg fully before adding the next. Stir in vanilla extract.

Gradually add the dry ingredients to the wet ingredients, alternating with the coconut milk, beginning and ending with the dry ingredients. Mix on low speed until just combined, being careful not to overmix.

Fold in the shredded unsweetened coconut.

Divide the batter evenly among the three prepared cake pans. Bake for 25-30 minutes, or until a wooden skewer inserted into the center comes out clean.

Let cakes cool in pans for 10 minutes before inverting onto wire racks to cool completely.

In a medium saucepan, combine diced mangoes, granulated sugar, and lime juice. Cook over medium heat, stirring occasionally, until mangoes soften and release their juices (about 5-7 minutes).

In a small bowl, whisk together cornstarch and cold water to create a slurry.

Pour the cornstarch slurry into the mango mixture, stirring constantly. Continue to cook for 1-2 minutes, until the mixture thickens.

Remove from heat and transfer the mango filling to a bowl. Cover with plastic wrap directly on the surface to prevent a skin from forming. Let cool completely in the refrigerator.

In a large mixing bowl, beat softened cream cheese and butter with an electric mixer until smooth and creamy.

Gradually add sifted powdered sugar, one cup at a time, mixing on low speed until incorporated, then increasing to medium-high until fluffy.

Beat in vanilla extract and coconut extract (if using).

Add coconut milk, 1 tablespoon at a time, until the frosting reaches a smooth, spreadable consistency. Be careful not to make it too thin.

Once the cake layers are completely cool, use a cake leveler or a serrated knife to level the tops of the cakes if necessary, creating flat surfaces.

Place one cake layer on your serving plate or cake stand. Spread about 1/2 to 3/4 cup of coconut cream cheese frosting evenly over the top.

Pipe or spoon half of the cooled mango filling over the frosting, leaving a small border (about 1/2 inch) around the edge.

Carefully place the second cake layer on top. Repeat with another layer of frosting and the remaining mango filling.

Place the third cake layer on top. Apply a thin layer of coconut cream cheese frosting all over the cake (top and sides) for a crumb coat. This seals in any loose crumbs. Refrigerate for 15-20 minutes to set the crumb coat.

Apply the remaining frosting to the top and sides of the cake, smoothing it with an offset spatula. Garnish with toasted shredded coconut.

Refrigerate the cake for at least 30 minutes before slicing and serving, to allow the frosting to firm up.