01 - Preheat oven to 350°F. Grease and flour two 9-inch round cake pans.
02 - In a medium mixing bowl, whisk together flour, baking powder, baking soda, and salt.
03 - In a large bowl, beat unsalted butter and granulated sugar until light and fluffy with an electric mixer.
04 - Add eggs, one at a time, beating well after each addition. Blend in vanilla extract.
05 - Add the flour mixture to the butter mixture in three parts, alternating with coconut milk, beginning and ending with the flour. Mix until just combined.
06 - Gently fold in shredded coconut and crushed pineapple until evenly distributed.
07 - Evenly spread the batter into prepared cake pans. Smooth the surface. Bake 35 to 40 minutes, or until a toothpick inserted in the center emerges clean.
08 - Let cakes rest in pans for 10 minutes, then carefully transfer to a wire rack to cool completely.
09 - In a small saucepan, combine crushed pineapple, sugar, and cornstarch. Cook over medium heat, stirring continuously, until the mixture thickens (about 3–5 minutes). Allow to cool fully.
10 - Beat softened cream cheese and unsalted butter together until smooth. Gradually add powdered sugar, mixing until fluffy. Blend in vanilla extract and coconut milk.
11 - Place one cake layer on a serving plate. Spread cooled pineapple filling evenly over the surface.
12 - Top with the second cake layer. Frost top and sides with prepared cream cheese frosting using an offset spatula.
13 - Adorn the cake with toasted coconut, blueberries, strawberries, and, if desired, patriotic sprinkles.