#1 Moist Sponge Cake:
#2 Mikan Curd:
http://travelingpastryhunter.blogspot.com/2016/09/citrus-curd-recipe.html
Use mikan/tangerine/madarin orange juice for the citrus juice, along with the zest from the fruit you picked.
#3 White Mirror Glaze
(So, the recipe I used in the video of this dessert is a really bad one, so please ignore that recipe and use this once instead.)
#4 Assembly:
Slice the cooled cake into three horizontal layers. Place the first slice into the bottom of a container that fits it snugly and top it with a layer of chilled mikan curd (line the container first with clear cling wrap so that you can easily remove it later). Repeat once more, then top with the last layer of cake and freeze the entire dessert for at least 1 hour, or until frozen through.
Remove from the container and trim or smooth down the sides until you like the look of the cake. Return to the freezer while you re-heat your glaze. Once the glaze has reached between 90-94F, take out your cake, place it on a stable item that is slightly smaller than it, with a pan or baking sheet underneath everything to catch the excess glaze. Pour the glaze over the entire cake, making sure to cover all sides. Let the glaze finish dripping off, then go ahead and smooth off the bottom edges and move directly to a serving platter. Put the cake in the fridge for an hour to defrost (will take longer if it is a larger cake) before serving.