Whisk the egg whites and cream of tartar in a large bowl until the mixture reaches a thick consistency that leaves stiff peaks on your whisk. During the mixing process, gradually add the sugar until the desired consistency is reached.
Process for Cake Batter
Preheat your oven to 340°F or 170 °C
Sift the all-purpose flour and baking powder into a mixing bowl then add the salt and white sugar. Mix until the ingredients are well incorporated then set aside for later.
In a different bowl, pour the egg yolks, milk, ube flavoring, and ube halaya and mix them well. Once the wet ingredients are incorporated, gradually add the dry ingredients and carefully stir the mixture until it reaches a smooth consistency.
Once the batter reaches a smooth consistency, carefully add the meringue and fold it into the batter.
In 2 6×6 pans with parchment paper, place half of the ube cake mixture for each pan. Make sure to gently tap the pans to remove any air bubbles.
Bake it for 28-35 mins.
You can check if the cake is ready by poking a toothpick and seeing if it comes out clean. Once the cake is ready, remove it from the pans by carefully flipping it over a cooling rack then remove the parchment paper.
Process for Frosting and Assembly
Add the cream cheese, white sugar, and vanilla then beat them together until it reaches a smooth consistency. During the mixing process, gradually add the all-purpose cream.
After creating the frosting, cut the cakes in half then take one of the four layers and grind it up using a grinder or blender. You can also try using a fork so long as you reach a result where the crumbled cake can be used to decorate the sides of the cake.
Layer the remaining pieces of cake with frosting in-between each layer then cover the sides with frosting and apply the crumbled cake. Make sure to leave enough frosting to transfer into a pipping bag.
Simply pipe a circle of swirls on the edge of the surface and your cake is ready.