Preheat the oven to 200°C (180°C fan) and line a baking tray with baking parchment.
Put two Celestial Seasonings Raspberry Zinger tea bags into 60 ml boiling water and leave to infuse for 5 minutes. Discard the bags and set the tea aside to cool completely.
In a large bowl, whisk together the plain flour, caster sugar, baking powder and salt.
Add the cold, cubed butter and rub it into the flour with a pastry cutter or your fingertips until the mixture resembles coarse breadcrumbs with some pea-sized pieces.
In another bowl or jug, lightly whisk the milk, egg and cooled tea, then pour this into the flour mixture. Stir until just combined.
Gently fold in the dried cranberries until no dry streaks remain.
Turn the dough out onto a lightly floured surface and pat into a circle about 2 cm thick. Cut into 8 wedges or use a 6 cm round cutter.
Place the scones on the prepared tray and bake for 15–18 minutes, until golden and cooked through when tested with a skewer.
Leave the scones on the tray for a few minutes, then transfer to a wire rack to cool slightly. Serve warm with clotted cream or jam.