Sweet Potato Cake

If you're Asian, you've definitely had this cake at some point.


If you've never had it before, a sweet potato cake might sound bizarre, but trust me, it works. The sweet potatoes used in this cake are different from the orange ones found in American grocery stores, much sweeter and almost thicker in texture. The sweet potato cream is super smooth, rich, creamy, and has a nice natural sweetness. Roasting the sweet potato adds a caramelized note to it as well, but boiling them is also a great option if you're short on time. 

I made this cake for my roomie Grace's 20th birthday! I can't believe it's already that time when my friends and I are turning 20. Not having a 1 in front of my age just throws me off. Technically, nothing much is different about 20 compared to becoming an adult on your 18th or legal on your 21st, but as a kid, 20 seemed like an age super far away. Now 19, it still seems super far away but it's actually right around the corner. 

20s seem like the golden age, when the prime time to explore the world, your dreams, and yourself. Just the thought of it fills me with excitement. But it's also a little daunting, thinking that its also the decade where most people settle down with a job and get married. Both of those things seem absolutely unthinkable now, as I'm probably still going to be slaving away in med school/residency and I haven't even gone a single date before. 

I always talk about how the huge gap between my internal age and actual age, but I wonder if this will continue until I die or if there's a certain point when I actually feel like my age. This all sounds like gibberish, but I dunno, thoughts about the future have been on my mind lately. 

Anyway, back to the cake! My other roommate Jessica and I made some effort to decorate it, and it's definitely not award-winning pastry status, but as Jess said, it has a rustic Studio Ghibli vibe to it. Whatever age you are, young or old, this cake will definitely be enjoyed.

Recipe

Genoise Cake
For 1 9x5 loaf pan (double if using normal cake pan)

2 eggs, room temperature
20 g melted butter (1 1/2 tbsp)
20 mL milk (1 1/2 tbsp)
50 g sugar (1/4 cup)
50 g flour (I used AP flour, but definitely recommend cake flour here. Didn't come out as fluffy as I expected.)
1/4 tsp baking powder

1. Preheat oven to 350 C. Prepare pan with parchment paper.
2. Separate eggs into yolks and whites. Whisk yolks until slightly paler in color. Add milk, melted butter, and vanilla. Whisk to combine.
3. Whisk egg whites on low speed until foamy. Add 1/4 of sugar. Continue to whip on medium to high speed, adding the rest of sugar in 2 or 3 increments. Whip to stiff peaks.
4. Sift in flour and baking powder over yolk mixture. Fold carefully.
5. Fold meringue mixture into yolk mixture carefully, keeping the mixture as airy as possible.
6. Pour batter into prepared pan. Knock out air bubbles by dropping pan on counter a couple times.
7. Bake for 15-20 minutes (25-30 min for a bigger cake). Cool to room temperature on cooling rack.

Sweet Potato Cream
2 sweet potatoes, roasted or boiled
40 mL heavy cream (3 tbsp)
40 mL milk (3 tbsp)
17 g sugar (1.75 tbsp)
17 g butter (1 1/4 tbsp)

200 mL heavy cream (for whipped cream)

1. Mash sweet potatoes in a bowl until smooth. In a small saucepan, heat the cream, milk, sugar, and butter over medium-low heat. 
2. When the mixture is simmering, turn off the heat and add the mashed potatoes. Using an immersion blender, blend until smooth. Another option is sieving the mixture to make it smooth.
3. Whip the heavy cream. Add about 1/2 cup of whipped cream to the sweet potato mixture to lighten it up. 

Assembly
1. Cut the cake in half. Using a spatula or knife, spread some of the sweet potato cream into an even layer. Place the other half of the cake on top.
2. Place a good amount of whipped cream on top of the cake. Smooth the cream all over the cake. 
3. For extra decoration, I put the remaining whipped cream and sweet potato cream in 2 piping bags and alternated piping little dots along the bottom of the cake. On the top, I just piped the sweet potato cream into even rows.