Method

1. In a medium sized mixing bowl, sift together the flour and sugar. Add in the cold / cubed butter and mix until it resembles sand. You can mix by hand or in a food processor.
2. Add in the ice water 1/2 tablespoon at a time until the dough comes together. It may require 1-2 tablespoons of ice-water. You want the dough to be smooth and slightly sticky, but not too dry or wet.
3. Wrap the dough in some grease proof paper and place into the fridge for 30 minutes or until it feels firm. This will help to prevent sticking when you roll it out.
4. Preheat oven to 170°C fan and line 2 baking trays with grease proof paper.
5. Lay a sheet of grease proof paper on your worktop and dust with some flour.
6. Roll out the dough in-between 2 sheets of floured grease proof paper until its a large rectangle. Use a sharp knife to cut the dough into a diamond shape (approximately 10cm on each side). Place on the lined trays. Repeat until you’ve used up almost all the dough. Use a mini heart shaped cookie cutter to use out shapes with the remaining dough.
7. Spoon a teaspoon or two of strawberry jam into the middle of the diamond shapes. Fold three of the corners into the centre (sides and bottom) so that the pastry looks like an open envelope. Press the corners in to seal the jam in (refer the images above for examples).
8. Brush the pastry with some dairy-free milk and stick on the hearts into the center (see photos for reference). Sprinkle over some sugar, this will help give the pastry a golden colour and will also make it crispy on top.
9. Bake the pastries in the middle of the oven for 20-25 minutes, or until the pastry is golden brown in colour.
10. Once baked, remove from the oven and allow to cool. The pastry will be a little soft when first out of the oven, but will crisp up beautifully. 
11. Serve with a sprinkling of icing sugar. You could even add a drizzle of a simple glaze on top, but I personally think they’re perfect without it.