Mont Blanc Roll Cake

Directions

1. 1
   Make the Mont Blanc cream.
2. 2
   Prepare the All-Purpose Cream Chestnut Paste
3. 3
   Add the chestnut paste and sugar into a small saucepan and mix together.
4. 4
   Press the mixture through a strainer to make it smooth.
5. 5
   Mix in the rum once cooled.
6. 6
   Add the sugar into heavy cream and beat until stiff peaks form.
7. 7
   Mix 1/5 of this whipped cream into the mixture from Step 2 and the Mont Blanc cream is done!
8. 8
   Make the roll cake batter.
9. 9
   Line a 30 cm x 30 cm baking sheet with parchment paper.
10. 10
    Preheat the oven to 180C.
11. 11
    Put the egg whites into a bowl, and whip into a firm meringue while whisking in the sugar in 2 batches.
12. 12
    In a different bowl, whisk together the egg yolk and sugar.
13. 13
    Mix in the vegetable oil in 2 batches.
14. 14
    Also mix in the milk in 2 batches.
15. 15
    Sift the cake flour into the mixture and whisk well.
16. 16
    Add 1/4 of the meringue and fold in thoroughly use an electric mixer for everything up to this point).
17. 17
    Change to a rubber or wooden spatula and fold in the rest of the meringue, being careful not to break the foam.
18. 18
    Pour batter into the baking sheet and smooth out the surface.
19. 19
    Bake for 15 minutes at 180C.
20. 20
    Remove the baking sheet from the oven, and let it cool after sticking plastic wrap on the surface.
21. 21
    When it's cooled, spread the leftover whipped cream from Step 3 (set a little aside) over the surface and roll it up.
22. 22
    Let it rest for a while in the fridge, and cut into appropriate widths.
23. 23
    Spread the set aside whipped cream on top of the cake, and pipe out the Mont Blanc cream.
24. 24
    Dust the cake with powdered sugar if you like.
25. 25
    I got a little lazy here and spread the Mont Blanc cream inside m