In a small saucepan, combine fresh or frozen raspberries, granulated sugar, water, and cornstarch over medium heat. Mash the mixture while cooking for about 5–10 minutes until it thickens to a jam-like consistency. Set aside to cool.

In a mixing bowl or food processor, mix all-purpose flour, vegan block butter, and powdered sugar. Blend until it resembles coarse crumbs and gradually add cold water to form a pliable dough.

Roll the dough out to about 5mm thickness and cut out circles to line the mini tart tins. Press the circles into the tins, patching any cracks with excess dough.

Preheat your oven to 180°C (350°F) while you fill the pastry shells with roughly 1 tablespoon of cooled jam. Bake for approximately 20 minutes until golden brown.

Remove the tarts from the oven and let them cool in the pans for a few minutes before transferring to a wire rack to cool completely.