Heat oven to 180C/160C fan/gas 4.
Lightly butter a few baking trays. In a
large bowl, beat together the butter,
sugar and egg until smooth. Sift in the
flour, cinnamon and baking powder,
then combine to make a dough. Add
the sultanas and 100g of the white
chocolate, and mix to combine.
Roll lumps of dough into balls the
size of golf balls. Flatten these onto the
trays, leaving enough space between
each for them to expand. Bake for
10 mins until golden (you may have to
do this in batches). Remove the cookies
from the trays and cool on wire racks.
Melt the remaining white chocolate
in the microwave on Low in 20-second
bursts. Using a small piping bag or a
teaspoon, carefully drizzle a cross on top
of each cookie. Leave to set before
eating. These cookies can be stored
in a cookie jar for up to 3 days.