1. Tip the flour into a large mixing bowl and add the salt, sugar and cinnamon to one side of the bowl and the yeast to the other. Add the butter and three-quarters of the water, and turn the mixture round with your fingers. Continue to add the water, a little at a time, until you’ve picked up all the flour from the sides of the bowl. You may not need to add all the water, or you may need to add a little more – you want dough that is soft, but not soggy. Use the mixture to clean the inside of the bowl and keep going until the mixture forms a rough dough.
2. Coat the work surface with a little vegetable oil, then tip the dough onto it and begin to knead. Keep kneading for 5-10 minutes. Work through the initial wet stage until the dough starts to form a soft, smooth skin.
3. When your dough feels smooth and silky, put it into a large, lightly oiled bowl. Cover with a tea towel and leave to rise until at least doubled in size – at least 1 hour, but it’s fine to leave it for 2 or even 3 hours.
4. Line 2 baking trays with baking parchment or silicone paper.
5. Tip the sultanas and mixed peel on top of the risen dough in the bowl and start working them into it. After a minute or two, tip the dough out onto a lightly floured surface and knead until the fruit is thoroughly mixed in.
6. Divide the dough into 8 pieces. Shape each into a ball, then use a rolling pin to flatten each out to a round bun, about 1cm thick. Brush the teacakes with the beaten egg. Transfer to the prepared baking trays, spacing them apart.
Put each tray inside a clean plastic bag and leave to rise for about an hour until the teacakes are at least doubled in size. Meanwhile, heat your oven to 200°C.
Bake the teacakes for 10-15 minutes until risen and golden. Cool on a wire rack.