Lately, I'm experiencing a wave of good cooking/baking karma. I've been cooking more than ever before and the constant practice is paying off big time. I can't believe how delicious everything is turning out. Even unintentional mistakes result in unexpectedly wonderful results. This is rather unusual in baking where precision is everything. This baked mochi cake is a prime example.
Leading up to the Lunar New Year, I've been craving baked mochi cake (nian gao). It is a fad that started in the last decade, I think. I still remember one year when my mom came back from work clutching a hand-scribbled recipe and a piece of cake that her coworker made. It looked like a slice of good ol' pound cake but the chewy soft texture was unmistakeably like mochi. Nowadays you can buy this delicacy at most Chinese bakery around New Year. It's not traditional in the strictest sense but I love eating them nonetheless.
A quick search on the internet and I found a few recipes for baked butter mochi with more of a Hawaiian lineage. The recipes are simple enough that my mind immediately wandered to all the creative possibilities. Before I knew it, I returned home from my local Japanese grocer with boxes of mochiko (sweet rice flour) and a big bag of Ueno black raw sugar. Black raw sugar is a cousin of the more famous Okinawa kurozato. They both have very distinctive taste and is highly prized in making sweets. I've been looking for a reason to incorporate that in my baking and I think I've finally found a good venue.
An extra layer of complexity is added by the use of beurre noisette. This is where my happy accidental discovery happened. Unlike refined sugar, these lumps of raw sugar take a long time to melt so instead of a mixture of melted butter and sugar, I ended up with beurre noisette. Such irresistably nutty aroma! This cake is only mildly sweet which reminds me of the western sweets in Japan. The characteristic chewy texture of mochi is maintained in this baked version though subdued compared to traditional steamed mochi.
I love to pair this cake with a cup of steaming green tea or even matcha for a Japanese style afternoon tea. For a more decadent take, drizzle with syrup made from kurozato to highlight the black sugar flavour. Added bonus: gluten-free cake!
Ingredients
- 454g of mochiko (sweet rice flour)
- 2 tsp of baking powder
- 227g of unsalted butter, cut into pieces
- 300g of black raw sugar
- 1 can (370mL) of evaporated milk
- 2 tsp of vanilla extract
- 4 eggs
Method
- Preheat oven to 350F. Grease and flour two 5" round cake pans.
- In a large mixing bowl, whisk together mochiko and baking powder. Set aside.
- Put butter and sugar in a small pot over medium low heat. Stirring occasionally, cook until all the sugar has melted, about 20-25 minutes.
- Stir butter mixture into evaporated milk. Add vanilla extract.
- Stir in eggs until batter is smooth.
- Pour butter mixture into flour mixture. Fold until flour is completely incorporated. You want to be gentle but don't worry too much about overmixing because unlike wheat flour, this batter does not develop gluten. Woohoo!
- Divide batter between two cake pans. Bake for 45 minutes until toothpick inserted into the cake comes out with only a few moist crumbs.
See how big the lumps of sugar are? That would take some time to cook. 
After 25 minutes, butter has turned into beurre noisette (take a whiff of that nutty smell) and all the sugar has melted. Dark liquid gold. I want to eat this off a spoon but common sense told me it's burning hot. That would be dumb.
Thick and smooth. The evaporated milk ought to cool down the mixture so it would not cook your eggs into scrambled eggs in the next step. 
A nice shade of mocha brown. If you want to be extra careful, you can cool the batter down a bit at this point.
Time for some elbow grease. But not too much. 
Finally the batter is ready. Very thick indeed.
Unlike me, you want to smooth the batter because that little bump showed up in the final product. Oops. 
Enjoy! I hope you'll like this cake as much as I do!