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Recipe Detail Page
Rocky Road Truffle Cakes
Early Summer 2004
The combination of chocolate, walnuts and marshmallow make this little cake a delight for the diehard sweet tooth. Making the marshmallow layer is easiest with the use of a candy thermometer, but the recipe is flexible enough to be done without one - just time the cooking sugar for 7 minutes after it starts a full boil. Glucose syrup can be purchased at a specialty cake store or bulk store. These cakes will keep for 1 day refrigerated or 2 days covered at room temperature.
Makes 16 little cakes for petit fours or 9 individual cakes for desserts
Brownie Layer
2 1/2 oz (75 g) bittersweet chocolate, chopped
1/2 cup plus 1 tbsp (140 mL) unsalted butter at room temperature
2/3 cup (150 mL) sugar
2 large eggs
1 tsp (5 mL) vanilla extract
1/2 cup (125 mL) all-purpose flour
1/4 tsp (1 mL) salt
1/2 cup (125 mL) walnut halves, lightly toasted
Marshmallow Layer
Cornstarch, for dusting
1 tbsp plus 1 1/2 tsp (22 mL) gelatin powder
1/2 cup (125 mL) cold water
1 cup plus 3 tbsp (295 mL) sugar
2 tbsp (25 mL) glucose syrup or white corn syrup
2 large egg whites
1/2 tsp (2 mL) vanilla extract
Truffle Ganache
1/2 cup (125 mL) whipping cream
4 oz (125 g) bittersweet chocolate, chopped
2 tbsp (25 mL) unsalted butter at room temperature
Garnish
Walnut halves, optional
1. For Brownie Layer, preheat oven to 350°F (180°C).
2. Grease an 8-inch (20-cm) square pan and line with parchment so that paper hangs over sides of pan.
3. Melt chocolate in a bowl over a pot of gently simmering water, stirring constantly. Cool chocolate to room temperature and stir in butter by hand until smooth. Stir in sugar gently and add eggs, one at a time, until blended. Stir in vanilla. Gently mix flour and salt into chocolate and stir in walnuts. Scrape batter into prepared pan and bake for 19 to 22 minutes, until cake takes on a dull colour and feels firm when touched. Allow to cool completely.
4. For Marshmallow Layer, line an 8-inch (20-cm) square pan with parchment, and dust generously with cornstarch.
5. Sprinkle gelatin over 1/4 cup (50 mL) of cold water, stir and set aside for 5 minutes. Melt gelatin over low heat and keep warm.
6. Bring remaining 1/4 cup (50 mL) water, sugar and glucose syrup to a boil over medium-high heat and cook until sugar reaches 245°F (118°C) on a candy thermometer, 7 minutes.
7. While sugar is cooking, whip egg whites with electric beaters or in a mixer fitted with the whisk attachment, until foamy.
8. When sugar reaches the proper temperature, pour it carefully in a stream down the side of the bowl while mixing on medium speed. Once incorporated, pour in melted gelatin and vanilla and whip mixture on high speed until thick and white, about 4 minutes. Pour marshmallow into prepared pan, sift top with cornstarch to prevent sticking, and let set for at least 2 hours before unmoulding.
9. For Truffle Ganache, heat cream to just below a simmer and pour over chopped chocolate. Let sit 1 minute, then stir slowly until evenly blended. Stir in butter until melted in. Let cool for at least 30 minutes, or chill until ready to assemble.
10. For assembly, remove brownie from pan in 1 piece by lifting parchment overhang. Brush top of brownie with a layer of ganache (if ganache sets up, just re-warm to melt). Brush excess cornstarch off marshmallow and turn over onto brownie. Peel off parchment from marshmallow carefully. With a hot knife, cut dessert into 9 or 16 squares and arrange on a platter. Once truffle ganache has cooled enough to pipe, pipe a swirl on top of each square. Each cake can be garnished with a toasted walnut half if desired.
Makes 16 little cakes for petit fours or 9 individual cakes for desserts
