Pre-heat the oven to 200°C, 180°C fan, 390° F Gas Mark 6.
Grease 8 holes of a muffin tin with butter being sure to include the top edges.
Unroll croissant dough onto worktop and cut down the middle with a dough scraper to give 2 pieces.
Pinch together the perforations to eradicate all the holes in the dough sheets.
Using a pastry brush, paint the melted butter onto the dough sheets.
In a bowl, mix the light Muscovado sugar, caster sugar and cinnamon together with a small whisk (to get rid of any lumps).
Sprinkle the cinnamon sugar evenly over the dough sheets with a tablespoon.
Even out with a dough scraper and use it to press the cinnamon sugar into the melted butter.
Roll the dough sheets up tightly from the shortest length to form 2 logs.
Then use the dough scraper (or a sharp knife) to cut each log into 4 equal rolls.
Stretch out the loose ends of each roll and tuck underneath whilst pushing up slightly. If needed, fan out the layers of dough with a knife if they’ve clumped together.
Place cinnamon rolls into the prepared muffin tin and then bake in the oven for 12 – 14 minutes until dark golden brown.
Remove from the oven and allow to cool for 2 minutes.
Then use a palette knife to turn each cinnamon roll on its side (to stop them sticking to the tin) and allow them to cool for another 2 minute.
Mix the sugar and cinnamon together for the coating.
Roll each croissant cinnamon roll in the cinnamon sugar to evenly coat.
Then place on a wire rack.
Serve warm for the best eating experience but can also be enjoyed cold.