11tablespoonsunsalted cold buttercut into thin slices
5tablespoonsice wateruse more if needed
Make the Crust. In bowl of a stand mixer, stir together flour, sugar, salt. Alternately, you can do this in a food processor.
Add cut up butter. With the paddle attached and mixer set on medium low, run for about a 1 ½ minutes or until mixture starts to look crumbly and butter is dispersed (or process in pulses). With mixer on low, add the water and mix just until the mixture comes together – be careful not to overwork it. Empty onto a clean surface and shape into a disc. Wrap in plastic wrap and chill for 1 hour or until ready to use. Let dough sit on counter for about 20 minutes.
Roll into a large circle and fit into a 9 inch deep dish pie plate so that it covers sides. Cover with foil, weigh down with pie weights. Bake at 425 for 15 minutes. Remove foil and pie weights and bake for another 5-10 minutes or until golden brown. Let cool.
Make the filling. Set aside 1 cup of the blackberries and put remaining 4 cups of blackberries in a medium saucepan. Combine sugar and cornstarch and pour over berries, stirring so that they are coated in the sugar mixture. Turn heat to medium and cook for about 8-10 minutes, stirring and mashing as you go, until berry mixture boils, thickens and the cornstarch loses its chalkiness. Remove from heat, pour into a bowl and stir in the lemon juice. Let the berry mixture cool for about an hour.
Mix together the cream cheese, sour cream and sugar and spread across cool baked pie shell. Scatter the reserved 1 cup of the fresh blackberries across the cream mixture. Pour the cooked berries over the top and chill for 3 or more hours.
Cook time includes approximate chill time. It's just an estimate.