The night before you want to bake the tea loaf, place the tea bags and the dried fruit in a large bowl and pour over 300ml (1 ¼ cups) of just boiled water. Give it a stir then cover and leave to soak overnight.
The following day, preheat the oven to 180°C/160°Cfan/350°F/gas mark 4. Grease a 900g/2lb loaf tin and line it with greaseproof paper.
Mix together the self-raising flour, sugar, baking powder and mixed spice in a large bowl.
Add the soy yogurt and the fruit mixture, including the soaking liquid. Squeeze the teabags to get all of the flavour out then throw them away.
Stir everything together to form a batter, making sure that no dry patches remain. Pour the batter into the prepared tin and spread it level.
Bake the tea loaf for 1 hour until a skewer inserted into the centre comes out clean. Leave it to cool in the tin for a few minutes before turning it out onto a wire rack to cool completely.
If you want the loaf to have a glazed, sticky finish, heat the marmalade with a splash of water in a small pan until it is runny then brush it over the top of the loaf while it is still warm.