Raspberry Bûche de Noël

By tulawdog

Ingredients

• For the syrup:
• 30 grams (2 tablespoons + 1 teaspoon) unrefined blond cane sugar
• 1 tablespoon dark rum or rosewater
• For the cake base:
• 4 large organic eggs, separated
• 100 grams (1/2 cup) unrefined blond cane sugar
• 100 grams (3 1/2 ounces, about 3/4 cup) all-purpose flour
• 1/4 teaspoon fine sea salt
• For the filling:
• 120 grams (1/2 cup) plain Greek-style yogurt or fromage blanc
• 120 grams (1/2 cup) mascarpone cheese
• 20 grams (1 tablespoon + 2 teaspoons) unrefined blond cane sugar
• 1 fresh pod vanilla (or 2 teaspoons vanilla extract)
• 230 grams (8 ounces) raspberries, fresh in season, frozen otherwise (no need to thaw)

Preparation

Step 1

Prepare the syrup.
Put 60 ml (1/4 cup) water and the 30 grams (2 tablespoons + 1 teaspoon) sugar in a small saucepan and heat just enough for the sugar to dissolve. Set aside to cool and add the rum.
Prepare the cake base.
Preheat the oven to 175°C (350°F). Have ready a metal jelly roll pan (sides greased and bottom lined with parchment paper) or a silicon jelly roll pan (no need to grease or line), about 28 by 38 cm (10 by 15 inches).
Run a clean kitchen towel (not terry cloth) under running water and wring it thoroughly so it is just moist.
In a medium bowl, whisk together the egg yolks and the 100 grams (1/2 cup) sugar until pale and fluffy.
Sugar + yolks
Fold in the flour, mixing just until incorporated.
Sugar + yolks + flour
In a separate, perfectly clean bowl, and using a perfectly clean whisk, whisk the egg whites with the salt until they form soft peaks.
Beaten egg whites
Stir one third of the egg whites into the batter to loosen. Fold in another third, working gently with a spatula to lift the mixture and keep it from deflating. Repeat with the remaining third.
Batter
Pour the batter into the prepared pan and level the surface with a spatula.
In mold
Bake for 8 to 10 minutes, until the top of the cake is golden. Don't overbake or it will be hard to roll.
Cooked base
Top the cake with the moist kitchen towel, place a baking sheet or tray over it, and flip the whole thing. Unmold the cake carefully, removing the parchment paper if present.
Unmolded
Brush the cake with the syrup, and roll it up with the kitchen towel; this will initiate the proper shape to make the final rolling easier. Let cool completely, seam side down.
Rolled
Fill and roll the bûche.
In a bowl, whisk together the yogurt, mascarpone, 20 grams (1 tablespoon + 2 teaspoons) sugar, and vanilla.
Yogurt + mascarpone
Unroll the cake carefully and spread it with the yogurt mixture (in the photo I didn't spread the filling up to the edges, but that's not necessary.) Arrange the raspberries on top.
Filled
Roll the cake back up as tightly and evenly as you can, using the kitchen towel for support (but not rolling it up this time).
Transfer cautiously to a dish or platter, seam side down, cover loosely with plastic wrap, and refrigerate for at least 4 hours, and up to 8.
Rolled
Serve the bûche.
Using a serrated bread knife, slice off both ends of the roll to get clean edges. Dust with confectioner's sugar and serve.