1.Preheat oven to 180ºC. Grease two 24cm x 32cm swiss roll pans and line bases and long sides with baking paper, extending paper 5cm over sides
2.To make ginger cake, sift flours, soda and spices into a large bowl; stir in brown sugar. Combine butter and syrup in a small saucepan and stir over low heat until smooth. Stir butter mixture into flour mixture with egg and milk. Divide mixture between pans; bake about 10 minutes. Cool in pans.
3.Meanwhile, make lime filling. Sprinkle gelatine over juice in a small heatproof jug, then stand jug in a small saucepan of simmering water. Stir until gelatine dissolves. Cool 5 minutes. Beat cream cheese, sugar and rind in medium bowl with electric mixer until smooth; beat in cream. Stir in gelatine mixture.
4.Pour filling over one of the ginger cakes in pan; top with remaining ginger cake. Refrigerate 3 hours or overnight until firm before cutting.