This method of lining can be used for cake tins of any shape to prevent the cake sticking.
Put the tin on a sheet of baking paper and trace around the base with a pencil. Cut out the traced shape just inside the pencil marking.
Brush the inside of the tin with melted butter.
Position the piece of baking paper in the bottom of the greased tin. If applicable to the recipe, line the side of the tin.
Grease the baking paper inside the tin, then sprinkle with plain flour and rotate to coat the base and side evenly. Tap out any excess flour.