250 grams self-raising flour
pinch of salt
fine zest of ½ lemon
125 grams butter, diced
150 ml milk
½ cup blackcurrant jam
1 egg yolk
2 teaspoons milk
raw sugar for sprinkling
Preheat the oven to 180°C and lightly grease a 35 cm x 30 cm piece of baking paper.
Put the flour, salt, lemon zest and butter in a food processor and pulse to form coarse crumbs. Add the milk and pulse again to form a soft dough. Tip onto a floured bench and roll out to a 30 cm x 25 cm rectangle.
Spread the jam over the dough, leaving a 1 cm border. Combine the egg yolk and the milk and brush over the border. Fold in the short sides and roll the dough into a cylinder.
Place seam side down on the baking paper. Brush with the egg wash and sprinkle with raw sugar. Roll up loosely and tie the ends with kitchen string. The dough needs space to expand while cooking.
Place seam side down on a baking tray and cook in the oven for 30-35 minutes until golden brown.
Cut off the paper and place the roly-poly on a serving platter. Cut into thick slices and serve with custard or cream.