In a medium saucepan, combine raspberries, sugar, water, and cornstarch. Cook over medium heat for 5-10 minutes, mashing berries as they soften until thickened and glossy. Remove from heat and cool.

In a large bowl or food processor, mix flour, vegan butter, powdered sugar, and cold water until the dough clumps together. Form into a ball, wrap in plastic, and chill for 10 minutes.

Roll out dough to ¼ inch thickness on a floured surface. Cut out circles to fit mini tart tins, gathering scraps to use again.

Preheat oven to 350°F (180°C). Grease tart tins and press dough circles in. Fill with 1 tablespoon of cooled jam.

Bake for about 20 minutes until edges are golden brown. Let cool in tins for a few minutes, then transfer to a wire rack.