In a bowl, mix together the mashed banana, melted butter, eggs and vanilla. Add the soaked apricots and any remaining tea. In another bowl, mix together the teff flour, sugar, baking powder and bicarbonate of soda. Pour the wet mixture over the dry mixture and mix briefly to combine. Pour into the prepared loaf tin, levelling with a knife. Sprinkle over the streusel topping and bake for 35 minutes or until a skewer inserted into the centre comes out clean. Check after 25 minutes to see if the top is getting too dark, if it is, cover loosely with foil.