Cake with Matcha Buttercream, Vanilla Biscuit, and Mascarpone-Blueberry Filling

Vanilla Biscuit: Preheat the oven to 185°C. Grease two baking pans and dust with flour.

In a food processor, beat the eggs, sugar, and vanilla seeds at high speed for about 5 minutes until light and fluffy.

Mix the cornstarch with the flour and sift it gently into the egg-sugar mixture. Fold everything together lightly.

Divide the batter between the two baking pans and bake for 20 minutes. Check by gently pressing; if the biscuit springs back, it is done.

Let cool for 5 minutes, remove the pans, and let cool completely on a wire rack.

Mascarpone-Blueberry Filling: Heat the blueberries with the juice and zest of the mandarin (or orange) and honey in a saucepan. Bring to a brief boil and then let cool completely.

Whip the mascarpone until smooth and gently mix with the cooled blueberries. Place the mixture in a piping bag.

Matcha Buttercream: Beat the eggs and egg yolks with the vanilla seeds.

In a saucepan, heat the sugar and water to 118°C (use a sugar thermometer). Remove the vanilla pods and carefully pour the sugar syrup in a thin stream into the beating eggs. Let cool for a few minutes.

Add the butter, piece by piece, and the matcha. Beat until smooth, creamy buttercream.

Assembling the Cake: Place one vanilla biscuit on a turntable and spread a thin layer of matcha buttercream in the center to secure the biscuit.

Pipe a ring of matcha buttercream around the edge of the biscuit and fill the center with the mascarpone-blueberry filling.

Place the second biscuit on top and press down lightly. Spread a thin layer of matcha buttercream on the top and sides and refrigerate for 1 hour.

Then finish the cake with a thicker layer of buttercream and smooth the sides and top with a palette knife.

Decorate with maraschino cherries on top of the buttercream roses.