Preheat the oven to 180°C (350°F) Gas 4.

Split the sweet shortcrust pastry dough into two equal portions and roll into 2 evenly sized squares, around 3 mm/1/8 inch thick. Each one should be around 30 x 30 cm/11 x 11 inches. Ensure the shapes are the same size as you will be layering them later.

Put the pastry squares on the prepared baking sheets. Prick the surfaces with a fork to prevent air bubbles forming as they bake. Pop in the preheated oven to bake for about 10–12 minutes or until slightly golden. Remove from the oven and set aside to cool on a wire rack.

On one of the cooled pastry sheets, spread a generous, even layer of the raspberry jam/jelly. Very carefully, slide the other piece of pastry on top so that it sits exactly on top of the base. Handle delicately, as the pastry can break quite easily.

Mix the icing/confectioners’ sugar with hot water to form a smooth paste. The amount of water you will need varies depending on your sugar. If the paste is too thick, add a few drops more water. Too thin, add a bit more icing/confectioners’ sugar. Aim for the consistency of runny honey. Spread the icing/frosting on top of the pastry to evenly cover. Top with sprinkles and leave to dry.

Using a very sharp knife, cut the edges off the pastry to make straight sides. Cut into 12 large or 16 small equal pieces to serve.