400g dark choc 270g unsalted butter 300g light brown sugar 100g golden caster sugar 5 large eggs 1 tsp salt 25ml coffee 190g plain flour 50g cocoa 150g white choc (optional) 1. Melt the dark chocolate over gently simmering water in a heatproof bowl set to one side. 2. Brown the butter in a pan, allow to cool for 5 mins then add to the melted chocolate and stir well. 3. Crack the eggs into another mixing bowl, whisk for 1-2 mins then add the two types of sugar and whisk again for another 2 minute

How Satellite push-broom and whisk-broom scanners work (Landsat8 & Landsat7, respectively)