Place the thickened cream, mascarpone, egg yolks, icing sugar and vanilla seeds in a stand mixer fitted with the whisk attachment and whisk on high speed until stiff and well combined. Chill until needed.

3. Combine the orange juice and Grand Marnier in a separate bowl. Dip half the sponge fingers into the juice mixture and layer in the base of the prepared pan. Spread with one-third of the mascarpone mixture, and top with one-third of the mango slices

Repeat the process, then top with the remaining mascarpone mixture, reserving the remaining mango slices to serve. Cover the cake and chill for 2 hours or until firm.