When making praline, caramel must be cooked significantly darker than you might expect - taken almost to the point of burning. This deep amber, nearly mahogany colour means that enough bitterness has developed to counterbalance the sweetness of the sugar and the natural richness of the nuts. A pale caramel produces a praline that tastes flat and one-dimensional. Watch carefully as the colour deepens: caramel continues to cook from residual heat after the pan leaves the hob, so remove it just before it reaches your target shade. Pour it onto a non-stick mat immediately to arrest the cooking.