Place the batter ingredients in a large bowl. Beat well with a wooden spoon until smooth, then leave in a warm place until frothy for about 20 minutes.
For the dough, place the flour in a bowl and rub in the butter until the mixture resembles fine breadcrumbs. Add the rubbed in mixture and egg to the batter. Mix well. Turn out onto a lightly floured surface. Knead for about 10 minutes, until the dough feels firm and elastic.
Place the dough in a lightly floured bowl. Cover with greased clingfilm and leave to rise for about 1 hour, or until the dough has doubled in size and will spring back when lightly pressed.
Pre-heat oven to 200 °C / 400 °F / Gas 6 and lightly butter a 20 cm (8 inch) sandwich tin. Knead the dough lightly. Roll out into a rectangle, 20 x 30 cm (8 x 12 inches). Spread the dough with butter and sprinkle with the sugar, fruit and mixed peel. Roll up like a Swiss roll from the long side. Cut into 9 slices.
Place 8 slices, cut sides downwards, around the edge of the tin and the remaining one in the centre. Cover and allow to rise for about 1 hour until the dough has doubled in size.
Uncover and bake for 30 to 35 minutes, until golden brown. Remove from the oven and brush with a little golden syrup to glaze. Leave to cool in the tin for 10 minutes, then turn out and leave to cool completely on a wire rack.