2 8-ounce packages cream cheese, room temperature
1 cup (2 stick) unsalted butter, room temperature
1/2 cup canned sweetened cream of coconut
3 1/2 cups powdered sugar
2 tablespons corn starch
1 teaspoon vanilla extract
1 tablespoon lemon juice
4 cups sweetened flaked coconut, toasted
Stir cornstarch, 2 tablespoons water, and coconut rum in small bowl to dissolve cornstarch. Bring cream, sugar,salt and butter to boil in heavy medium saucepan. Add cornstarch mixture and bring to boil. Remove from heat and stir in coconut. Cool completely. Mix in sour cream. Cover and refrigerate 2 hours or overnight. Cover with plastic wrap pressed down on filling to prevent skin from forming.
Preheat oven to 325░F. Butter and flour three 9-inch round cake pans. Whisk flour, baking powder, baking soda and salt in large bowl to blend. Using electric mixer, beat sugar and butter in another large bowl to blend. Add eggs 1 at a time, beating well after each addition. Beat in buttermilk, sweetened cream of coconut, coconut rum and vanilla. Fold flour mixture into butter mixture. Divide batter equally among pans. Bake until tester inserted into center of cakes comes out clean, about 35 minutes. Cool completely.
Using electric mixer; beat cream cheese, cream of coconut and butter in large bowl to blend. Beat in powdered sugar, corn starch, lemon juice and vanilla extract.
Place 1 *trimmed cake layer on cake board and/or plate. Top with half of filling. Place second *trimmed cake layer atop filling. Top with remaining filling. Place third *domed side up cake layer atop filling. Spread frosting over top and sides of cake. Pat toasted coconut over top and sides of cake, pressing gently to adhere. (Can be prepared up to 1 day ahead. Cover and refrigerate. Let stand at room temperature 3 hours before serving.) You can use 2 10 inch cake pans if the height intimidates you.
*You want to trim the 1st and 2nd layers flat to keep this cake level. The to layer is left with the best round top (dome) for that perfect look.
**Such as Coco LÚpez. Canned sweetened cream of coconut, such as Coco Lopez, is available in the liquor section of most supermarkets nationwide.