Pre heat the oven to 200C, fan 180C/gas 6.
In a large bowl, beat together the butter, WHITWORTHS LIGHT SOFT BROWN SUGAR and egg until light and fluffy. Sift in the flour, cinnamon and baking powder and combine to make a dough. Add the sultanas and 100g of the white chocolate and mix well.
Roll the dough into walnut-sized balls and flatten slightly. Place on lined baking trays, making sure you leave enough space for the cookies to spread. Bake in batches for 10 mins until golden. After 30 seconds, carefully transfer to a cooling rack.
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.
Allow the chocolate to set before serving!