Soak the raisins, then mix together with all ingredients except the yogurt. Mix in as much yogurt as it takes for the dough to stick together, and knead.
Roll out the dough on a floured surface to be about 2.5 cm (approximately 1 inch) thick and about 5 cm in diameter (approximately 2 inches). Place on a parchment paper-lined baking sheet, brush with beaten egg yolk and bake in a preheated oven at 200°C (approximately 400°F) for about 10-15 minutes, or until golden brown.
Serve with butter and jam and a dollop of whipped double cream.
Serve with tea, if desired.