Steps
- Mix 300g of self-rising flour, 1 tablespoon of cornstarch, 2 tablespoons of granulated sugar, and 1 large pinch of salt. Rub in 150g of cold butter until crumbly, then work in 150g of cream cheese.
- If dry, add 1 tablespoon of ice water. Knead briefly for 30 seconds, divide into two disks using two-thirds for the base, wrap, and chill for 1 hour.
- Rinse and drain 600g of blackberries, then mix with 100g of granulated sugar. Butter a 9in / 23cm pie dish.
- Roll the larger disk on a floured surface and line the dish, leaving an overhang. Toss the berries with 2 tablespoons of cornstarch, add them and their juices, and dot with 25g of butter.
- Preheat the oven to 400°F / 200°C with a baking sheet inside. Roll the remaining dough over the filling, seal and crimp the edges, and cut two small steam vents.
- Beat 1 egg with 1 tablespoon of milk and brush over the pastry. Bake on the hot sheet for 20 minutes.
- Brush again with egg wash, dust with granulated sugar, and bake for 20-25 minutes, until deep golden with bubbling juices. Cool for 30 minutes.