Julkaksmörkrokar med ägglikörsmak

👩‍🍳 Gör så här

1. 1
   Beat the butter and both sugars in a large bowl using an electric whisk until creamy. Add the egg yolks and vanilla, whisk to combine, then add the flour, custard powder, a grating of nutmeg, the cinnamon and a pinch of salt. Mix until everything clumps together into a dough.
2. 2
   Roll small pieces of dough into cherry-sized balls (about 10g each), then arrange on a baking tray lined with baking parchment. Squash each down slightly using a fork. Chill for at least 30 mins or up to a day. Will keep frozen for two months.
3. 3
   Heat the oven to 180C/160C fan/gas 4 and bake for 12-15 mins until golden and firm to the touch. Cool completely, then dust the tops lightly with icing sugar.
4. 4
   For the filling, beat the ingredients together using an electric whisk until smooth, then spoon into a piping bag fitted with a large round nozzle. Pipe a dot of icing on the flat side of half the cookies. Sandwich with the plain cookies. Will keep in an airtight container for three days.