• Preheat the oven to 340°F (170°C). Spray a 9-inch (23cm) springform pan with cake release, or grease with softened butter and dust with flour, shaking out any excess. Line the bottom of the pan with parchment paper.
• Sift the flour and cocoa powder into a large bowl. Add the sugar, baking powder, baking soda and salt and mix together with a balloon whisk.
  2 ½ cups (300g) all-purpose flour, ⅔ cup (60g) unsweetened cocoa powder, 1 ⅔ cups (330g) superfine sugar, 3 tsp baking powder, 1 ½ tsp baking soda, ½ tsp salt
• Add the butter, eggs, orange zest and juice.
  ⅞ cup (200g) unsalted butter, 3 large eggs, 3 oranges, zest only, ¾ cup (180ml) orange juice
• Start beating on the lowest speed setting until the ingredients start to come together.
• Increase the speed gradually, until the batter is completely smooth. Stop the mixer and scrape the sides and bottom of the bowl to make sure everything is incorporated.
• Transfer the batter to the prepared pan, level the top and make a small dip in the center so it rises evenly. Bake for 50 minutes to 1 hour. If the cake is browning too quickly, loosely tent with foil after 25 minutes, leaving a gap above the pan so the cake can still rise.
• The cake is done when it is well risen, springy to the touch and a skewer inserted in the center comes out clean.

Orange Drizzle (optional)

• While the cake is cooling in the pan for a few minutes, stir the sugar and orange juice in a saucepan over low heat until the sugar dissolves.
  ½ cup (100g) sugar, ½ cup (120ml) orange juice
• Poke holes all over the cake with a skewer, then pour the syrup over the top so it soaks in.
• Run a knife around the edge of the pan and transfer the cake to a plate. Leave to cool completely before adding the chocolate glaze.

Chocolate Glaze

• Put the chocolate chips and chopped Terry’s Chocolate Orange segments in a heatproof bowl. Heat the cream until small bubbles appear around the edges of the pan, pour it over the chocolate and leave to stand for 2–3 minutes.
  ⅔ cup (100g) dark chocolate chips, 3 segments Terry's Chocolate Orange, ½ cup (120ml) heavy cream
• Add the golden syrup or honey, then stir slowly with a small balloon whisk, starting in the center of the bowl and working outward, until the chocolate melts and the glaze is shiny and smooth.
  1 tbsp golden syrup
• Leave the glaze to cool slightly so that it drips slowly off a spoon. Pour over the cooled cake, letting it drip down the sides – you might not need all of the glaze.
• Leave the glaze to set slightly then decorate with segments of Terry’s Chocolate Orange and orange zest.
  1 Terry's Chocolate Orange, 1 orange, zest strips only