- 125g/4½oz unsalted butter, softened
- 125g/4½oz icing sugar, portioned into 100g/3½ oz and 25g/1oz parts, both sieved
- 25g/1oz ground almonds
- 3 free-range eggs, whites only
- 165g/5¾oz plain flour, sifted
- 1 to 2 oranges (depending on size), zest only
- 1 tsp orange extract
- 200g/7oz white chocolate, finely chopped
- 1 tsp cardamom pods, seeds only, ground
- Preheat the oven to 170C/350F/Gas 4.
- Beat the butter until very, very soft (preferably using an electric stand mixer) and there are no lumps, then beat in 100g/3½oz icing sugar for a minute.
- Sift the ground almonds and remaining icing sugar together over the mixture and stir in.
- Continue mixing, adding the egg whites one at a time.
- Then mix in the flour.
- Add the orange zest and orange extract.
- Leave the mixture to rest for 20 minutes.
- Meanwhile, mark out 7cm/2¾in lines, set at least 3cm/1¼in apart, on baking parchment, to guide where to pipe the biscuits. Flip the paper over and pipe on the unmarked side (the lines will show through).
- Fill a piping bag fitted with 1cm/½in plain nozzle with the biscuit mixture and pipe out. Smooth the tips down at the end of the line with a finger wetted in water.
- Bake for 8-9 minutes until the pale biscuits are just colouring and the centre is just golden-brown, with the edges slightly darker. This may take up to 10-12 minutes.
- Remove the biscuits from the oven and leave on the tray for 1-2 minutes. Using a palette knife transfer the biscuits to a wire rack to cool. Alternatively you can leave the biscuits to dry out and cool on the tray if slightly underdone.
- To decorate, combine the chopped chocolate and ground cardamom seeds.
- Melt two-thirds of the chopped white chocolate very gently in a heat-proof bowl set on top of a pan of simmering water. Heat the chocolate to no more than 45C/113F (use a thermometer to measure this), remove from the heat and then add the remaining white chocolate, stirring continually until the temperature drops to 32C/90F. Transfer to narrow or steep sided small bowl.
- Half dip each biscuit in the chocolate and then lay flat on baking parchment to dry.