I was talking to a friend recently about the use of vegetables and squashes in cakes after we both watched a food programme that featured a chocolate beetroot cake. My friend was quite horrified by the use of beetroot and even more so when I told her that almost any vegetable could be used as a cake ingredient. She refused to believe that adding any vegetable would taste good in a cake, despite my protests that she already knew and liked carrot cake. I was determined to prove her wrong and surprise her with a piece of cake that contained a secret vegetable ingredient, but which one to choose? I thought it over and in the end settled on a sweet potato. They are not strictly a vegetable but neither are they a common cake ingredient and I thought their sweet flavour would be a good starting point. Now all that was left was to find the right recipe to bake with it.
After much hunting I decided to adapt a recipe for pumpkin cake that I found on Culinary Concoctions by Peabody blog. I also fiddled around with the quantities and added orange zest and spices which I thought would complement the sweet potato.
Everything went well and the resulting cake was very good. It was moist and a lovely golden yellow colour thanks to the sweet potato. The mix of orange and spices tasted fantastic and gave it a very autumnal feel. The chopped pecans added a nice crunch and they had got nice and toasty during baking. It rose well during baking but sank slightly as it cooled down with the result that the base was a little denser then I would have liked (I think 5 mins more would have been ideal – I’ve amended the recipe). All my family loved this cake, and it’s one I would certainly make again, but I wanted to experiment further, so I’m calling this sweet potato cake version 1, with version 2 to follow.
Sweet Potato, Orange & Pecan Spice Cake (Version 1)
1 small or ½ large sweet potato (130g cooked flesh)
180g plain flour
2 tsp baking powder
1 tsp cinnamon
½ tsp nutmeg
¼ tsp cloves
2 eggs, separated
150g and a separate 30g caster sugar
1 tsp vanilla
Zest of ½ orange
40g pecans for decoration
Preheat the oven temperature to 180C. Grease and line two small loaf tins.
Prick the sweet potato and microwave on high for 9 minutes.
When the sweet potato is cooked, scoop out the flesh and mash until smooth. Measure out 130g of potato puree and set aside.
Sift the flour, baking powder, cinnamon, nutmeg, and ground cloves. Set aside.
In a clean bowl, beat the egg whites until they form soft peaks. Gradually beat in the 30g of sugar and continue to whisk until the egg whites are fairly stiff.
In another bowl combine the sweet potato, butter, vanilla, orange zest and remaining 150g sugar. Beat until light and fluffy. Add the egg yolks one at a time, making sure to scrape the sides of the bowl after each egg yolk is added.
Add a third of the flour mix, followed by half the milk. Repeat with more flour, milk and ending with the last of the flour.
Using a spatula, fold in a third of the egg whites into the batter to lighten it. Carefully fold in the remaining egg whites until no streaks remain, but do not over mix and deflate the batter.
Spread the batter between the loaf tins. Roughly chop the pecans and scatter over the surface. Bake for 40 minutes or until a cake tester comes out clean. Let the cakes cool in the tins for 10 minutes before turning out onto a wire rack and leaving to cool completely.
Makes two small loaves.
Note: I think this mixture would also fit into one deep 450g/1lb loaf tin and would probably need around 50-60 minutes cooking time.