Mt. Blanc Swiss Roll Recipe

Autumn only means one thing for me, and that’s chestnuts! Unlike in Japan where I get to eat Mt. Blanc year round by simply visiting the closest pastry shops, I have to wait for chestnuts to be in season before I get to sample them in the States. And even then, the shops here tend to skimp on the chestnut cream filling, so the best way is to make them myself. My love for Mt. Blanc was influenced by my mum, who as a kid was absolutely spoiled by my grandma’s homemade chestnut cakes. While I’ve never tasted my grandma’s cakes and will sadly, never have a chance to ask for her recipe, I hope mine does justice and make her just as proud. Since I’m chestnut crazy, the following recipe uses an inordinate amount of the ingredient (and you’ll most likely have quite a bit left over). If you’re like me, you’ll just eat the chestnut cream by the spoonful after stuffing the cake, but if not, you can keep the cream for 3-4 days in an airtight container for another chestnut based dessert.

Ingredients:

1 lb of chestnuts (boiled and peeled)

Cake (25cm X 25cm pan)
3 eggs (room temperature)
65g superfine sugar
80g cake flour
60g whole milk
40g oil (a neutral oil like grapeseed that doesn’t have a strong flavor)
1 teaspoon vanilla essence

Chestnut Cream
300g chestnut paste (sweetened)
240g chestnut puree
150g butter
2 teaspoons rum (you can add more if you like)
60ml whipping cream
50ml whole milk

Chantilly Cream
150ml whipping cream
7g sugar

Candied Chestnuts
4-5 chestnuts
50g sugar
35g water
1 teaspoon vanilla essence

Instructions:

1. Lightly rinse the chestnuts and score an X-mark on one side with a knife. Boil the chestnuts for about 20-25 minutes or so before turning off the fire. When peeling, try to take them out one by one, because it’s very hard to peel the inner skin when the chestnuts cool. (In my case, I had to turn on the fire to heat them back up a few more times). They’re very hot to work with, so be careful!
2. Set aside 300g for the chestnut puree in the chestnut cream, 4-5 chestnuts for the candied chestnuts, and the rest for filling the cake. You’ll undoubtedly have some left over, so feel free to snack on as you work!
3. Chop some of the chestnuts roughly into large pieces for filling the cake later on.
4. In a blender, crush the 300g of chestnuts on high speed until it forms a paste. If you have a Vitamix or some equally powerful blender, this saves a lot of work since it makes an extremely smooth paste. If not, you may have to press the paste through a sieve by hand, which takes quite a bit of time.

Candied Chestnuts

Note: I didn’t plan ahead for making the cake, so I didn’t get true candied chestnuts, which will take about 3-4 days to make. The chestnuts don’t soak up all the syrup in this recipe, so you’ll get a sweetened shell at most with the original texture of the chestnut intact, but it’s perfect for those who want only a slight hint of sweetness. For true candied chestnuts, I recommend NotQuiteNigella’s recipe.

1. Melt the sugar and water together over medium heat. Drop the peeled chestnuts in and simmer for five minutes. Add in the vanilla essence.
2. Turn off the heat and allow chestnuts to soak for a couple hours.

Cake

1. Separate your egg yolks and egg whites in two bowls. Beat the egg yolks with half the sugar (32-33g) with an electric mixer until pale and fluffy. When you lift the whisk, the mixture should drop back in thick ribbons.
2. Add in the milk, oil, and vanilla essence and mix thoroughly.
3. Add in all the flour, and incorporate thoroughly with the electric mixer. You can mix it with the highest speed, and the mixture should also drop back in thick ribbons that doesn’t disappear right away when you lift the whisk. (For the cake baking experts who’re doubtful of this step, trust me, it’ll work because of the fluffiness and air from the meringue).
4. In your other bowl, beat the egg whites on high speed until it forms soft peaks. Gradually add the rest of the sugar in while you continue beating. The meringue is complete when it forms stiff peaks.
5. Fold in 1/3 of the meringue into the cake batter mixture until incorporated. Don’t worry about crushing too much air since you want to lighten the batter before folding the rest of the meringue in. Fold the rest of the meringue in gently until incorporated (no more white spots left).
6. Pour into a 25 cm X 25 cm cake or jelly roll pan, and spread it evenly with your spatula. Bake at 170 degrees Celsius (or 335 degrees Fahrenheit) for 14-15 minutes. To check readiness, stick a toothpick in and make sure it comes out clean. Take your cake out and transfer on top of a cookie cooling rack.

Chestnut Cream

1. In a pot, combine the chestnut paste, chestnut cream, whipping cream, and butter over low heat. Transfer to a bowl and mix in the rum and milk. If you find the mixture too hard to incorporate smoothly, you can try beating it with an electric mixer on high speed like I did. My chestnut cream didn’t come out completely smooth, so I had to press it through a sieve with a spoon.

Chantilly Cream

1. Whip the cream and sugar together until fluffy. If you over whip (the cream forms airy clumps), you can easily save the mixture by adding a spoonful of cream and mixing gently.

Assembly

1. Place your cake on a large piece of clean parchment paper, and cut off one of the edges at a slanted angle so that it can close smoothly when you roll it.
2. Spread a generous layer of chestnut cream on top of the cake. Try to not spread any near the edge you cut off, so the filling won’t spill out after you roll it.
3. Spread the Chantilly cream evenly on top of the chestnut cream.
4. Line your chopped up chestnut pieces in three rows spaced apart parallel to the cut off edge. Again, try to not place the chestnuts too near the edge, or else your filling will spill out.
5. Gently row the cake into a roll, and tightly bunch the sides of the parchment paper into a candy wrapper like fashion. Place in the refrigerator and let it set for at least 1 hour. Don’t worry if your cake cracks in the middle, since you can decorate over it! When you’re ready to take the cake out for decorating, trim both edges so they’ll look neater.
6. To decorate, fill a piping bag with the remaining chestnut cream, and pipe in parallel squiggles like the picture above. Try to find a bigger piping tip than the one with multi-holes as it’s difficult to squeeze out sometimes. If you find it too hard to pipe, add more milk to the mixture and blend with a spatula to soften it.
7. Slice the candied chestnuts in half and place them on top of the chestnut cream. Garnish with chocolate, broken Pocky sticks (pictured above), mint, or if you’re feeling fancy, gold leaves if you wish.
8. Pop it back into the fridge for another hour before eating. Try to finish it within two days or so, for the outer chestnut cream decoration will harden in the refrigerator.

Enjoy! Let me know if you come up with other ways of decorating. I would love to see everyone’s pictures!

-Cynthia