Bake the cake: Preheat oven to 350° Fahrenheit. Grease three (3) 8-inch baking pans with cake release or vegetable oil and line the bottoms with parchment paper. Set aside. Sift the cake flour, salt, baking powder, and baking soda into a medium bowl and set aside.In a bowl of an electric mixer fitted with a paddle attachment, cream the sugar, butter, and coconut oil until light and fluffy over medium/high speed, about 3-5 minutes. Add the eggs one at a time, beating well after each addition. Quickly combine the sour cream, coconut milk, vanilla bean paste, and sweetened cream of coconut. Reduce the mixer speed to low and add the flour in three parts, alternating with the milk mixture. Mix until just combined. Turn the mixer off, and fold in the sweetened flaked coconut. Divide the batter into the baking pans. Place pans in the oven and bake for 30-35 minutes or until a cake tester or toothpick comes out with a just a few moist crumbs. Remove cake from the oven and allow to cool for about 5 minutes. Turn into a wire rack to cool completely before filling and frosting the cake. Make the filling:In a bowl of an electric mixer fitted with a whisk attachment (you can also use a hand mixer or a whisk and some serious arm strength), combine the cream cheese and guava paste. Mix over medium/high speed until combined. Turn off the mixer, scrape to combine, and add the confectioners' sugar. Turn the mixer speed to low and add the vanilla extract. Mix on low speed until the confectioners’ sugar is mostly combined with the guava/cheese mixture. Raise the speed to medium/high and add the heavy cream in a stream. Mix until the ingredients are fully combined and the filling is light and fluffy. NOTE: If you prefer a stiffer filling, feel free to add more confectioners’ sugar. A good rule would be to add 1 tablespoon at a time until you get the desired thickness. Wrap the surface of the bowl in plastic wrap and place in the refrigerator until ready to use.Make the frosting: In a stand mixer fitted with whisk attachment, cream the butter and shortening until combined, about 1-2 minutes.Reduce the speed to low and add salt, followed by the confectioners’ sugar one cup at a time, scraping down the sides of the mixer to incorporate.Add the vanilla bean paste, flavoring, and milk. Increase the speed to high and mix until light and fluffy, about 3-5 minutes.Add the heavy cream in three parts, ensuring it thickens completely before adding additional heavy cream. Mix until light and fluffy. Transfer to a tightly sealed container and place in the refrigerator until ready to use.Transfer 1/2 cup to a piping bag fitted with a round tip. Transfer about 1 cup of buttercream frosting to a medium bowl and color as desired. Transfer it to a piping bag fitted with a star tip. Set both aside briefly.To assemble the cake:Place one layer of cake on a cake stand or serving plate. Pipe a thin border around the outer perimeter of the cake to keep the guava filling in. Spoon half the guava filling in the center of the buttercream border. Repeat with next layer. Place final layer on top and spread a thin crumb coat on the cake. Place the cake in the refrigerator and chill for about 20 minutes. Frost the top and side of cake with remaining buttercream frosting, smoothing the sides and top of the cake as best you can. Pipe a star tipped border on the top of the cake and decorate with sprinkles.