Blackberry Galette - cooking recipe

Ingredients

1/2 cup all-purpose flour
1/2 cup butter, cold, chopped
1/2 cup granulated sugar
10.5 oz frozen blackberries, thawed
1 tbsp cornstarch
1/3 cup sour cream
2 None eggs, whisked
1 tsp vanilla extract

Preparation

Process flour with butter and 1/4 cup sugar until mixture resembles fine breadcrumbs. Add 1-2 tbsp ice water and process until dough just comes together. Turn out onto a lightly floured surface and knead until smooth. Cover with plastic wrap and chill for 20 mins.
Preheat oven to 400\u00b0F. Line a baking tray with parchment paper. Roll pastry out into a 12 inch disc then transfer to prepared tray. Toss berries with cornstarch and arrange over pastry, leaving a 2 inch border. Gently fold pastry edges over berries. Whisk together sour cream, remaining sugar, 1 egg and vanilla then pour over blackberries. Brush edges with remaining egg and bake for 25-30 mins, until golden brown.