How to shorten the lifespan of your hand mixer. [Castella (Japanese Sponge Cake) Recipe]

We recently acquired a Kitchen-Aid stand mixer at the school I work at. Excited by the new purchase, my coworker and I took it on a test run with our students. We made strawberry thumbprint cookies and egg white cake. I'm pretty sure I wet myself when I used the new tool to dominate the egg whites. It's a beast and I'd do anything to get one into my house. After the near death experience for my hand mixer during the creation of marshmallows, I thought about purchasing a stand mixer. After using and witnessing the speed, power, efficiency, and sexiness of a stand mixer, it's not an "if" anymore. It is a MUST!

Too bad I didn't have a stand mixer in my possession when I was making the castella sponge cake, because the technique this recipe required nearly choked the life out of my hand mixer. The hand mixer was agreeable, felt healthy, and worked well in the beginning, but at the 15 minute mark, the mixer began wheezing. By 20 minutes, it was begging for a break. When 30 minutes hit, the mixer was coughing, grinding it's motor, and running a high fever. Lucky for me, the batter reached the proper consistency before the mixer experienced a heart attack.

Was the near death experience with my mixer worth it? Yes. The cake was chewy and dense with a lovely scent of honey sweetness. It was a tad too sweet for me so I will probably cut down on the honey glaze next time or add matcha powder into the batter to help cut the sweetness. (I did mix some of the leftover batter with matcha powder and I loved the taste of it.)

Kasutera (Castella)
originally from JustHungry

My Notes
(1) Please read recipe completely before beginning.
(2) Please use a stand mixer if you don't want to shorten the lifespan of your hand mixer.
(3) If using a hand mixer, use the largest bowl you can find, the batter will expand considerably. Near the end,  the batter was on the very edge of the bowl and bits of it was sloshing out.
(4) A 8x8 inch dish works fine, you'll have some leftover batter that can be baked in ramekins.
(5) A gallon sized Ziploc bag fits a 8x8 inch cake.

Ingredients
8 whole "large" (55g) eggs
300g (10.5 oz) raw cane sugar (In a pinch, use regular granulated sugar), plus a little extra sugar for sprinkling
200g (7 oz) all-purpose or bread flour (not cake flour), sift twice
100cc (about 1/2 cup, or 3.5 fluid oz) milk
4 TBSP honey, plus one extra TBSP. for the top

Directions

1. Preheat the oven to 170°C / 340°F, or 150°C / 300°F if you're using a convection oven.
2. Cut the parchment paper so that it's large enough to fit the bottom and sides of the cake pan with a little excess. Fold it in until it completely covers the bottom and sides, leaving a little hanging over. (To make it stick to the pan, smear a little butter or shortening on the pan first.) Sprinkle a little sugar over the bottom, on top of the paper.
3. Fill the pot with water and bring to a boil, then turn off the heat.
4. Mix together the milk and 4 tablespoons of honey. It helps if you warm it up for a few seconds in the microwave.
5. Break the eggs into the bowl and whisk. Add the sugar. Start whisking this while holding the bowl over the pot of hot water. As soon as the mixture feels lukewarm to the touch, take it off the water and continue whisking. If it cools down again, put it back on the hot pot of water to warm it up. To get the best texture, whisk mixture on lowest setting; it took me around 35 minutes on the lowest setting. If using a stand mixer, take the bowl and whisk by hand while it warms up above the pot. Once mixture is warm, return it to the stand and whisk on low until cool, then return it back to pot. 
6. Continue this process until the batter is thick and forms soft peaks when you lift up the whisk. Final test: write initials on surface with whisk and the batter should hold it long enough to be read before it disappears. 
7. Whisk in the milk and honey mixture. Add the flour a tablespoon at a time, beating on lowest setting until there are no pockets of flour (you can also mix this part by hand).
8. Pour the batter to the very top of the pan. Bake in oven for approximately 45 to 50 minutes. Check by sticking a knife or toothpick in middle. If it comes out clean, it's done. 
9. Five minutes before cake is done, mix together the 1 tablespoon of honey and a water, to make a glaze. Warm it up in the microwave for 10 to 15 seconds. 
10. As soon as the cake is out of the oven, brush the top with the honey-water glaze.
11. When it's cool enough to handle but still warm (about 15 minutes), lift it out of the pan, paper and all, and put into a plastic bag. Seal the bag and put into the refrigerator, for at least several hours. This step is critical to ensure the kasutera has a moist texture. If you let it cool to room temperature before putting it in the plastic bag, it will end up a bit dry.
12. To serve, use a very sharp knife to make clean cuts. Use only one cutting motion for each side of the cake. Do not use a sawing motion if you don't want an ugly edge to your cake.