Preheat the oven to 375 degrees.

In a bowl, combine the flour with the sugar and salt. Using your fingertips, mix in the cold coconut oil to form a crumbly mixture with some large, bean-sized pieces of oil (coconut oil melts at 76 degrees, and therefore, if your room is warm, you should chill the oil for a couple of hours first – it should be hard and solid). Mix in the cold water until the dough comes together.

Roll the dough out between two pieces of parchment until it is a large, rough circle about ¼ inch thick. Place on a baking sheet, intact with parchment on the bottom, and remove the top sheet.

Combine the berries, sugar, lemon zest and juice, and flour in a bowl, and mix to distribute ingredients. Place the berries on the crust, leaving a 1 to 1 ½ inch border all around. Fold the border over the berries. Bake for about 30 minutes until the crust is golden. Let cool briefly or completely before cutting and serving.

Before serving, sprinkle with powdered sugar.