Preheat your oven to 350°F (180°C) and line a baking sheet with parchment paper.
In a mixing bowl, combine the flour and sugar. Add the cold, cubed butter and rub it into the flour mixture until it resembles breadcrumbs.
Add the egg and mix until the dough comes together. If the dough is too dry, you can add a little bit of cold water.
Divide the dough in half and roll out each piece into a large rectangle on a floured surface.
Spread the raspberry jam evenly over one of the rectangles, leaving a small border around the edges.
Carefully place the other rectangle of dough on top of the jam-covered one and press the edges to seal.
Bake in the preheated oven for about 20-25 minutes, or until the pastry is golden brown.
Allow the hindbærsnitter to cool completely before icing.
In a small bowl, mix the powdered sugar with enough water to create a thick icing. Drizzle the icing over the cooled hindbærsnitter.
Cut the pastry into bars and enjoy!
