Hugh's Pfeffernusse

This was my second attempt at Pfeffernusse this year. These are more like the ones I recognise in the shops completely covered in icing. 

Pfeffernusse (from The Guardian)
(Makes 40)

2 eggs
230g soft light brown sugar
2 tbsp marzipan, warmed to a soft paste
250g plain flour
1 tsp baking powder
1½ tsp ground mixed spice
1 tsp freshly ground black pepper
 4 egg whites
Around 500g icing sugar
1 tsp kirsch (optional)

Line two or three baking sheets with baking parchment. Beat the eggs and sugar until fluffy and pale, then beat in the marzipan. Sieve the flour, baking powder, mixed spice and pepper, over the beaten eggs and stir to combine. Turn out on to a lightly floured work surface, knead into a smooth dough, cover and refrigerate for an hour. Preheat the oven to 150C.

With lightly floured hands, roll the mixture into about 40 balls of around 3cm in diameter and place on the baking sheets, leaving space for them to spread. Bake for 16-18 mins, until starting to turn golden around the edges. Peel the balls off the baking parchment while they're still warm, and leave to cool completely on a wire rack. 

To make the icing, you will need around one part egg white to four parts icing sugar, so weigh your egg whites before you start. In a clean bowl, beat the whites until stiff. Sieve the icing sugar and gradually fold it into the beaten whites until smooth. Stir in the kirsch, if using.

Dip each biscuit into the icing until coated all over, then place on a wire rack to allow the excess to drip off. Put them back on the parchment-lined trays and return to the now cooling oven, with the door open, for five mins to help them harden. Make sure the icing is fully hard on top and bottom before you try to move them. The cookies will be very hard at first, though they will soften slightly with time. The flavours will improve if you keep them in an airtight tin for a week or so.