This cake is soft and reminiscent of the filling in pumpkin pie. Not surprising really, when it has mashed sweet potato as its main ingredient.
To do ahead of time
Cook sweet potatoes in the microwave (or oven if you have it running for something else) until they are soft. Mine took about eight minutes - four small sweet potatoes. Leave to cool then remove the peel and mash. I found it easiest to cut an end off and scoop the sweet potato out with a circular action with a fork. Do this ahead of time so you don't be tempted to work with them while they are very hot and burn yourself. Keep the peel and spritz with oil, put on a baking sheet, and cook for 20-30 minutes in the oven for a crisp scoop for spicy salsa.
My muscovado sugar is always a solid lump. Hack enough sugar off and leave put in a bowl with the oil and eggs so it dissolves - this will make the rest of the cake making much easier.
400g mashed cooked sweet potato - mine was 460g whole (4 small)
125g muscovado sugar
125 ml oil
125 g self raising flour (mine is 40%urid, 40% tapioca, 20% rice, with 1 tsp bp for each 100g)
1 tsp mixed spice /pie spice
1 tsp cinnamon
Mix the sugar, oil and egg and leave for the lumps of sugar to dissolve if needed.
Mix in the cooled mashed sweet potato, flour and spices.
Pour the sloppy cake mix into a greased/lined tin. I used a 9inch square tin as I wanted a shallow cake.
Bake in a pre-heated oven, 175C fan, for 40-45 minutes until a knife inserted comes out clean.
Leave in tin for a few minutes on the cooling rack to allow it to firm slightly, then remove from tin and leave to cool, or eat hot as a pudding with icecream. If you want a firmer cake add some more flour or cut down on the sweet potato.