This is a slightly luxurious mont blanc tart... The combination of mashed sweet chestnuts and sweet potatoes and marron cream makes for the most delicious tart.
I used to make marron cream with candied chestnuts and heavy cream, but by blending sweet potatoes (mashed up with sweetened chestnuts), the cream became even more delicious.
Using a spongecake batter brought out the flavor of the marron more than almond cream. The whipped cream in Step 7 is made by adding (100 ml heavy cream, 10 g granulated sugar), and whipping.
Enjoy Japanese food around the world.