Place the milk and butter in a small saucepan over low heat. Cook for 2 mins or until butter just melts. Remove from heat.
Combine the flour, sugar, yeast, mixed spice, salt and dried fruit in a large bowl. Add the milk mixture and egg and stir to combine. Turn onto a lightly floured surface and knead for 10 mins or until dough is smooth and elastic. Return to the bowl. Cover with plastic wrap and place in a warm, draught-free place for 1 hour or until dough doubles in size.
Preheat oven to 200°C. Grease a 22cm square cake pan. Turn the dough onto a lightly floured surface and knead until dough returns to its original size. Divide evenly into 16 portions. Roll each portion into a ball. Arrange the dough balls, side by side, in the prepared pan. Set aside in a warm, draught-free place for 30 mins or until dough rises by 2cm.
To make the flour paste, combine the flour and enough water in a small bowl to make a smooth paste. Place in a small sealable plastic bag and cut off one small corner. Pipe flour paste over the tops of buns to make cross shapes.
Bake for 10 mins. Reduce oven to 180°C and bake for a further 20 mins or until golden brown and cooked through.
Turn buns onto a wire rack. Place jam in a saucepan over high heat. Cook for 2 mins or until jam melts. Strain through a fine sieve. Brush hot jam over buns. Serve warm or toasted with butter.