Prepare the Dough: In a bowl, combine the bread flour and salt.

Add the butter and pastry shortening (or extra dry butter) to the flour mixture.

Use your fingers or a pastry cutter to work the fats into the flour until the mixture resembles coarse crumbs.

Gradually add the water and mix until the dough comes together.

Form the dough into a ball, wrap it in plastic wrap, and refrigerate for at least 30 minutes.

Roll Out the Dough: Preheat your oven to 210-220°C (410-430°F).

On a lightly floured surface, roll out the dough to about 1/4 inch thickness.

Cut the dough into your desired shapes (rectangles, circles, etc.).

Add the Filling: Place a small amount of your favorite jam in the center of each dough piece.

Fold the dough over the jam to enclose it and press the edges together to seal.

Use a fork to crimp the edges for a decorative touch.

Prepare for Baking: Place the filled pastries on a baking sheet lined with parchment paper.

Brush the tops with egg yolk or egg yolk substitute.

Sprinkle with sugar for added sweetness and crunch.

Bake the Pastries: Bake in the preheated oven for 20-30 minutes, or until the pastries are golden brown and crisp.

Remove from the oven and let cool on a wire rack.

Serve: Enjoy these delicious pastries warm or at room temperature.

Serve with a cup of tea or coffee for a delightful treat.