Line a colander with thin cloth. Support the colander over a deep bowl.
Pour the curd into it and let it drain till 1 cup of thick curd cheese is left in the cloth.
Transfer the curd cheese to a bowl and add sugar. Beat till the sugar is dissolved.
Soak saffron in 1 tsp of warm milk. Crush and add to the curd cheese.
Add cardamom powder. This is Srikhand.
Peel the mango and cut a portion of the flesh into tiny cubes.
Slice the remaining flesh. Keep the Srikhand and mango in the refrigerator while preparing the cake.
Grease a Swiss roll tin and line with greased butter paper.
Sift the flour twice
Whisk the eggs, egg yolk and sugar together till the mixture leaves a trail when the whisk is lifted.
Beat in the essence.
Fold in the flour. Gently fold in the butter. Spread in the prepared tray. Bake in a hot oven (200 degrees centigrade) till done. (10-12 minutes) Turn out on a butter paper.
Remove the paper on top of the cake. Roll up with the paper at the bottom. Allow to cool.
Carefully unroll the cake. Reserve one and a half of Srikhand for topping. Spread the remaining over the cake.
Sprinkle mango cubes over it. Roll up the cake again (without the paper) and cover the roll with a piece of aluminium foil.
Chill in the refrigerator for 4-6 hours or until serving. Just before serving, remove the foil and place the roll on a serving plate. Spread the reserved Srikhand over the roll and decorate with mango slices.