Ingredients

1,2 kg sweet potatoes
75 gr ghee or coconut butter
1 teaspoon of vanilla powder
1 teaspoon of cinnamon powder
180 gr coconut sugar or brown sugar
3 eggs
 

Instructions

Boil sweet potatoes for 15 minutes.
Heat the oven to 140ºC
Grease a mould of 22 cm.
Mix sweet potatoes with butter, sugar and spices until smooth.
Add eggs one at a time and mix again.
Pour the mixture in the mould and bake for 20 minutes.
Descend the temperature to 125ºC and bake 40 minutes.
Let the cake to cold down and unmould.
Keep in the fridge.

Original recipe:  http://www.750g.com/gateau-de-patates-douces-et-vanille-r67574.htm#TtlXTVdPluQq4AEd.99
 

Other options

This another option is very interesting in order to make tasty cakes to the persons that have intolerances to eggs and all sweeteners but dried fruit. 
 

Ingredients

320 gr sweet potatoes or carrots or winter squash
100 gr dates puree
30 gr coconut butter
optional: vanilla or cinnamon powder, shredded coconut, carob powder, etc.
 

Instructions

Preheat the oven to 180ºC.
Grind well sweet potato or carrots or squash.
Mix sweet potatoes with butter, dates puree and rest of optional ingredients until smooth.
Pour the mixture in the mould and bake for 15 minutes.
Let the cake to cold down and unmould.
It may be eaten warm or cold.
Keep in the fridge.