Preheat your oven to 425°F (220°C).
Using a rolling pin, carefully roll out each sheet of puff pastry until it's slightly thinner and larger, approximately 10 x 10 inches.
Cut each puff pastry sheet into nine equal squares for uniformity. Then, prick each square all over with a fork to allow steam to escape during baking.
Place about 1 teaspoon of jam in the center of each square, brush the edges with egg wash, fold corners toward the center, pinch them together, and twist to seal.
Brush the outside of each tart with any remaining egg wash and sprinkle generously with turbinado sugar.
Bake your tarts in the preheated oven for about 15-20 minutes or until they're golden brown. Let them cool for at least 30 minutes before enjoying.