IT Was a sweet Christmas for Thorntons after strong sales of advent calendars and a new range of chocolates based on festive film favourite The Snowman helped it serve up a 6.3 per cent hike in sales. supermarket sales were once again the star performer for the confectioner, with UK commercial sales to other retailers leaping 21.1 per cent ahead in the 14 weeks to January 11. But its embattled high street stores returned to like-for-like growth, with sales up 3.5 per cent after slipping back by 0.4 per cent in the previous three months in a sign that turnaround efforts are bearing fruit. Total sales across the 281-strong estate fell 2.9 per cent to £46.1 million. Online trade was also robust, up 27 per cent.