Gluten-free banana and pecan cake

150g pecan nuts
350g gluten-free plain flour
2tsp xanthan gum
2 1/2tsp gluten-free baking powder
225g vitalite dairy spread
225g caster sugar
1/2tsp vanilla extract
4 large eggs
4 very ripe bananas
85g dark chocolate

Preheat oven to 180c/160c fan/gas 4.Line a 33 x 23cm shallow tin with baking paper.Put half the nuts on a baking tray and bake for 5 min until lightly toasted.Chop roughly.Sift the flour,xanthan gum and baking powder.In  a different bowl,beat the spread and sugar until creamy.Beat in the vanilla and eggs,one at a time,adding 1tbsp of the flour mixture with each egg.Mash the bananas with a folk,then fold into the mixture with the rest of the flour,chopped nuts and dark chocolate.Put in cake tin,level the top,scatter with the remaining nuts and bake for 40-45 mins or until the middle of the cake springs back when lightly pressed.Leave to cool.