Pour 700ml water into the pot. Spray or grease the bottom of 20cm round springform baking tin with cooking spray or oil and dust with flour. Line base with baking parchment.
Place flour, baking powder and spices into a medium bowl. Mix well and set aside.
In a large bowl, add sugar, oil and eggs and beat together, then gradually add flour mixture and mix until completely combined. Stir in carrots, nuts and orange zest until evenly combined. Pour the batter into prepared cake tin.
Place the pan on the reversible rack in the lower position, then place the rack in the pot. Close lid and move slider to middle position.
Select STEAM BAKE, set temperature to 160°C, and set time to 45 minutes. Press START/STOP to begin cooking (this will STEAM for approximately 20 minutes before switching to STEAM BAKE).
When cooking is complete, check if cooked by inserting a wooden toothpick into the middle of the cake. If it comes out clean, remove the rack with the pan and let cool for at least 1 hour. If the toothpick comes out with moist crumbs or batter stuck to it, continue to bake until the toothpick comes out clean.
While cake is cooling, in a large bowl, add cream cheese, butter and sugar and beat until creamy and smooth.
When the cake has cooled, cut cake in half horizontally and sandwich together with third of the icing. Spread the remaining icing on top and decorate with walnut halves or slivers of carrots.
