Heat the oven to 180°C. Lightly grease 6 holes in a muffin tin with butter or dairy-free spread. Or prepare 6 silicon baskets.
Combine the sugar and cinnamon in a small bowl.
Unroll the pastry and brush it with the melted butter. Scatter two-thirds of the cinnamon sugar over it, then roll it tightly into a long sausage shape (along its long side). Cut this into 3 equal sized logs.
Cut each log, lengthwise, into 2 pieces. You should get 6 thin pieces, exposing the inner layers on one side.
Take one piece and form a knot - preferably showing the layered side outwards. Repeat with the remaining pieces.
Place each piece in the greased tin or silicon baskets.
Bake for 20-25 minutes, in the middle of the oven, until golden.
Take the tin out of the oven, and using a spoon, remove the cruffins onto a plate.
Brush them with any remaining butter and roll them in the cinnamon sugar, while they’re still warm.
Let them cool before serving.