Step 1: In a large bowl, whisk together the flour, 1 tablespoon of sugar, and salt for the blackberry galette easy rustic beautiful crust.
Step 2: Cut the cold butter into the flour mixture using a pastry cutter or your fingers until it resembles coarse crumbs with some pea-sized pieces.
Step 3: Gradually add ice water, one tablespoon at a time, mixing until the dough just starts to come together. Wrap in plastic and chill for at least 30 minutes.
Step 4: Pre-heat your oven to 400°F (200°C) and line a baking sheet with parchment paper for your blackberry galette easy rustic beautiful.
Step 5: In a medium bowl, gently toss the blackberries with 1/4 cup sugar, cornstarch, and lemon zest to create the blackberry galette easy rustic beautiful filling.
Step 6: On a floured surface, roll the chilled dough into a 12-inch circle and transfer it to the prepared baking sheet.
Step 7: Arrange the blackberry mixture in the center, leaving a 2-inch border. Fold the edges of the dough over the fruit to create the blackberry galette easy rustic beautiful look.
Step 8: Brush the edges with beaten egg and sprinkle with turbinado sugar. Bake for 30-35 minutes until the crust is golden brown and the fruit is bubbly.
Step 9: Allow the blackberry galette easy rustic beautiful to cool for at least 15 minutes before slicing and serving.