Make the sponge cake. Add the egg white to a bowl. Add the sugar little by little while whipping until firm with a hand mixer.
Switch to a rubber spatula and add in the egg yolk at once. Mix together.
Add in the sifted ● ingredients in 2-3 batches and use a rubber spatula to cut in without kneading. Add the next batch right before the the previous batch completely blends in.
Heat the milk and butter together in the microwave. Add a small amount of the batter from Step 3 and mix in.
Return Step 4 into the bowl and mix in well. The batter is ready once it's thick like ribbons.
Line a pound cake mold with parchment paper and pour in the batter. Rap it against the counter 2-3 times to release air bubbles. Bake for 20-25 minutes in a 170°C oven.
As soon as it has finished baking, drop it from a height to prevent it from collapsing. Remove it from the mold and turn it upside down, with the parchment paper still on, to cool.
Scrape off the browned surfaces on the top and bottom with a knife. Slice into 3 equal pieces.
Peel off the skin of the orange with a knife. Neatly remove the seeds. Set aside some slices for the decoration.
The rest will be for the filling, so cut diagonally.
Mix together the heavy cream and the sugar and whip until soft peaks form. Add in the melted chocolate and whip until firm to make the filling.
Put the syrup ingredients in a container and heat in the microwave until the sugar dissolves. Let cool.
Spread the syrup onto the bottom layer of cake with a pastry brush. Then spread the heavy cream. Place the center piece of cake on top and spread more syrup.
Spread on some cream and lay the orange pieces. Thickly spread on more cream to cover the oranges. Top with the last layer of sponge cake.
Spread some syrup on the top surface and thinly spread on some cream.
Place the remaining cream into a piping bag with a mont blanc style piping tip. Pipe on the mont blanc topping. Cool in the refrigerator.
Dust the top surface with cocoa powder, cut the cake into 5 pieces, decorate, and it's finished!
Here is a strawberry version. Recipe ID: 1666993 Strawberry Mont Blanc Shortcake.
Here is a sweet potato version. Recipe ID: 1596698 Sweet Potato Mont Blanc Shortcake.
Here is a raspberry version. Recipe ID: 1733190. Raspberry Cheese Mont Blanc Shortcake.
Here is a matcha adzuki version. Recipe ID: 1765477 Matcha Chocolate Adzuki Mont Blanc Shortcake.
Story Behind this Recipe
When I was thinking about making a chocolate shortcake, I wanted to add strawberries for the filling, but they weren't in season. So I decided to use chocolate, which is available year round, and oranges, which pairs well with chocolate.
Before using the oranges, gently pat dry with a paper towel. If you take too long to whip the chocolate cream, it will become flat, so work quickly. Because of this, you should prepare the piping bag and cut the oranges ahead of time.