1 lemon, finely grated zest only
1 orange, finely grated zest only
125²µ/4½´Ç³ú caster sugar
icing sugar, for dusting
5g salt
500g/1lb 2oz strong white flour, plus extra for dusting
2 tsp vanilla paste
10g fast-action yeast
150g/5½oz softened butter, plus extra for greasing
2 medium free-range eggs (preferably Burford Brown or other dark yolked varieties)
2 free-range egg yolks (preferably Burford Brown or other dark yolked varieties)
100ml/3½fl oz milk, warmed