Mix the flour, salt, sugar and yeast in a bowl. Add the butter, milk and egg, mix and knead to form a soft, smooth dough. Cover and leave to rise at room temperature for approx. 1 hr. until doubled in size.
Mix all the ingredients in a bowl. Sprinkle a little flour on the work surface and roll out the dough to a rectangle of approx. 40 x 50cm. Spread the filling over the dough, leaving a free edge of about 1 cm. Roll the dough up from the long edge and, without exerting pressure, slice into about 10 pieces with a bread knife. Spread the swirls out evenly in the prepared tin, cover and leave to rise for another 30 mins. or so at room temperature.
for approx. 40 mins. in the lower half of an oven preheated to 180°C. Remove the cake, coat immediately with the jam, allow to cool in the tin for about 10 mins., remove from the tin, slide the cake onto a cooling rack, leave to cool.