Heat oven to 200C/180C fan/gas 7. Grease a 12-hole muffin tin well. Scatter the sugar over your work surface, unroll the croissant dough, then roll out on the sugar to a rectangle roughly double the size of this magazine, scattering with more sugar as you roll.
Cut the rectangle roughly into 12 squares. Bring the corners of each square together and scrunch them into the tin.
Scatter with more sugar and bake for 30 mins until puffed up, dark golden and caramelised – turn down the oven if they brown too quickly. Remove from the tin while they are hot (otherwise they’ll stick) and leave to cool.