Mix the flour and sugar together in a mixing bowl. Rub in the butter with your thumb and forefinger, add salt and squash, pat and push it into a dough. Don’t knead it, you just want to pat it down flat.Push or roll it out until it’s 1cm thick – do this directly on to a baking sheet lined with greaseproof paper so you don’t have to move it. Once it’s in the shape you like – which could be square, round, or a few small finger-shapes – feel free to thumb or pinch the edges. If it splits or tears, just press it back together – but remember, the less you work the dough, the shorter and better these biscuits will be.
Sprinkle over some caster sugar, then pop the baking sheet into the oven and cook for 20 to 30 minutes. Keep an eye on it – you want a lovely light golden colour.
Leave to cool, then put away in a tin or serve. These will be delicious for two or three days and make a lovely present for someone special.