We flavoured our truffles with vanilla bean paste but you can substitute with your choice of liqueur, if desired.
- 1½ cups plain flour
- ½ cup unsweetened good-quality cocoa
- ¾ teaspoon baking powder
- ½ teaspoon bicarbonate of soda
- pinch of salt
- 1½ cups caster sugar
- ¾ cup canola oil
- 3 eggs
- ¾ cup cold mashed potato
- ¾ cup buttermilk
- 600g good-quality dark chocolate, grated or finely chopped
- 300ml pure cream
- 1 teaspoon vanilla bean paste
- ½ cup cocoa, sifted
- 64 x 5cm-diameter rounds of tissue paper
CHOCOLATE BOX WALLS
- 200g dark chocolate
- 120g good-quality dark chocolate, grated or finely chopped
- 75ml pure cream
Preheat and grease
Preheat oven to 180°C. Grease a deep 20cm square cake pan and line with baking paper.
Sift flour, cocoa, baking powder, bicarbonate of soda and salt together into a bowl. Place sugar, oil and eggs in a separate bowl and whisk until well combined. Add mashed potato and whisk until smooth. Alternately fold in flour mixture and buttermilk, finishing with flour mixture until smooth and combined. Spoon into prepared pan.
Bake for 40–45 minutes or until a skewer inserted into centre comes out clean. Cool in pan for 10 minutes, then turn onto a wire rack to cool completely.
Using a serrated knife, trim top of cake so it is level with sides. Cut cake into four 9cm square cakes.
To make chocolate truffles, place chocolate in a heatproof bowl. Place cream in a small saucepan and bring just to a simmer over a medium heat. Pour hot cream over chocolate. Set aside for 3 minutes, then stir until smooth and well combined. Add vanilla bean paste and stir to combine.
Place chocolate mixture, uncovered, in refrigerator for 1 hour or until firm. Using clean hands, roll 1 teaspoonful of chocolate mixture into a ball. Place on a tray lined with baking paper. Repeat with remaining chocolate mixture to make 64 balls. Store in refrigerator until required.
To make chocolate box walls, cut out twenty 9cm x 6cm pieces of baking paper (allow an extra 4 for breakages). Place chocolate in a heatproof bowl set over a saucepan half-filled with simmering water (make sure bowl does not touch water), and stir with a metal spoon until melted and smooth. Remove from heat.
Place one 9cm x 6cm piece of baking paper on a lined chopping board. Using a palette knife, spread 1 tablespoon of melted chocolate over paper rectangle to cover. Transfer to a lined baking
tray. Repeat with remaining paper rectangles and chocolate. Refrigerate for 30 minutes or until set. Carefully remove paper from each chocolate rectangle. (If paper has curled, causing chocolate rectangle to curve slightly, turn chocolate rectangle over on tray and set aside at room temperature until flat.) Refrigerate until ready to use.
To make chocolate ganache, place chocolate in a heatproof bowl. Place cream in a small saucepan and bring just to a simmer over a medium heat. Pour hot cream over chocolate. Set aside for 3 minutes, then stir until smooth. Set aside at room temperature
for 30–40 minutes to cool or until ganache is thick but not hard.
To assemble, place 1 cake on a board lined with baking paper. Thinly spread sides of cake with chocolate ganache and gently fix 4 chocolate rectangles to sides so it resembles a box. Repeat with remaining cakes, ganache and chocolate rectangles. Refrigerate
for 15 minutes or until set. Meanwhile, sift cocoa into a shallow
dish. Roll truffles in cocoa to coat. Half wrap each truffle in a round of tissue paper and arrange on top of cakes.