FOR THE PASTRY
Cut your butter into small cubes of roughly 1cm using two knives to avoid touching it with your hands, and place it in a large mixing bowl.
Sift your flour, salt and icing sugar from a height into the bowl, to get the air into the ingredients. Gently rub the butter into the flours using your fingertips. A light touch here is important; lift up the flour as you do this and let it fall back into the bowl to create a lighter texture for the mix. You should end up with a breadcrumb-type consistency – don’t overwork it.
Mix your egg yolk with 2 tablespoons of cold water, and sprinkle it evenly over the mixture. Use a blunt kitchen knife or palette knife to incorporate it as quickly as possible and bring the dough together. If you need more water add it gradually and sparingly – you only need enough water to bind the dough. If your ingredients look dry then add some more water, but stop before it becomes wet and tacky; you want to end up with a soft dough.
Shape your dough into a disc and wrap it in cling film. Rest it in the fridge for 30 minutes.
Lightly flour your work surface. Roll your dough out into a large rectangle, roughly 2mm thick. Use a sharp knife or a pizza cutter to slice the dough into 8 rectangles of 7 x 11cm (you may need to reform some of the scraps as you go). Brush four of the rectangles with 1 scant tablespoon of peanut butter per rectangle. Brush the other four rectangles with 1 scant tablespoon of jam per rectangle, leaving a small border of 1-1.5cm for the crust around each.
Place each peanut butter half on top of a strawberry half, and use a fork to crimp the edges closed. Mix the beaten egg wash with the milk and glaze each pop tart using a pastry brush. Use a fork to prick holes in the top of each tart for the steam to escape.
Preheat your oven to 180°C and line a baking tray with baking parchment. Place your pop tarts on the baking tray and refrigerate for 30 minutes. Bake in the oven for 25-30 minutes, until the pastry is golden and cooked through.
Leave to cool on a wire rack before icing. Combine the icing sugar with the water until you have a thick but spreadable consistency. Scatter the coloured sprinkles on top while the icing is still wet, and leave to set.
Store in an airtight container in a cool dry place, for up to 3 days.
