Preheat oven to 220C/200C fan forced and line a large baking tray with baking paper.
Sift the flour, sugar and salt into a large mixing bowl. Make a well in the centre. Add the cream and soda water. Use a flat-bladed knife to mix until just combined. Gather the dough together and transfer to a lightly floured benchtop. Gently knead until just smooth. Press out to 2cm thick disc.
Use a 6cm round cutter to cut 12 rounds from the dough. Cut as close together as possible – the less re-rolling of offcuts the better.
Place the scones, just touching, on the prepared tray and brush the tops lightly with extra cream. Bake for 15 minutes until risen and golden brown. Transfer to a wire rack to cool.
Serve the scones with jam and cream.
