Recipe:

1. Preheat the oven to 180°C/160°C fan/4 gas mark. In a small bowl, mix together the cinnamon and caster sugar. Set aside.
2. In a food processor, add the plain flour, wholemeal flour, grapefruit zest, salt and cubed butter. Pulse blend until you have a mixture resembling sand. Add the vanilla, the juice of half the grapefruit and 2 tablespoons of cold water. Blend until the dough comes together and forms a ball. If the dough feels dry, add 1-2 tablespoons additional water.
3. Turn the dough out onto a floured surface and form into a ball. Divide the dough in half. Working with one piece of dough at a time, roll the dough as thin as you can. It should be about 4mm thick.
4. Transfer the dough to a large piece of baking paper. Brush the dough with the melted butter and sprinkle generously with the cinnamon sugar, making sure all the dough is covered. Cut into 2cm squares. Repeat with the remaining dough.
5. Carefully transfer the baking papers to baking trays and separate the squares, spacing them at least half a centimetre apart. 
6. Baked for 12-14 minutes, until golden brown. Let them cool completely then store in an airtight container for up to 7 days. Serve with your milk or yoghurt of choice and fresh fruits.