Preheat the oven to 375ºF (190ºC). Position oven racks to the upper third and lower third positions. Line 2 large half-sheet baking pans with parchment paper. Set them aside.

In a microwave-safe bowl, whisk together the glutinous rice flour, ginger, and brown sugar. Add the molasses and coconut milk and mix until you get a smooth batter. It’s okay if you see very tiny lumps of flour in the batter.

The cooking times may vary depending on the wattage of your microwave and the type of vessel/bowl you use to microwave the batter. Therefore, use the cooking times I provide here as guidelines, and pay attention to the visual cues. Microwave the nian gao batter on high for 1 minute.

Take the bowl out of the microwave. The batter should start solidifying around the edges, but should still be quite runny. Use a silicone spatula to loosen the cake around the edges and give everything a quick stir. It’s okay if you have a lumpy batter here.

Microwave the batter for 30 seconds. The batter should have solidified further. When testing the recipe in my microwave, 50% of the batter was still runny at this stage. Use the spatula to loosen the cake around the edges and give everything a quick stir.

Microwave the batter for another 30 seconds. When testing the recipe in my microwave, there was barely any runny batter left in my bowl. Use the spatula to work any residual runny batter into the dough and keep mixing for about 45 seconds to 1 minute, until you get a cohesive dough that has a rich brown color. If there’s still a lot of runny batter after 1 minute of mixing, microwave the dough for another 30 seconds and mix again. (See note 3 for steaming directions)

Let the nian gao cool for 15 to 20 minutes while you prepare the chocolate chip cookie dough. It is very important to let the nian gao cool so that it’s less sticky when you handle it later.

In a bowl, whisk together the all-purpose flour, ginger, cinnamon, baking soda, and salt. Set it aside.

Add the granulated sugar and orange zest into a bowl and use your fingers to work the zest into the sugar. The sugar should look orange by the end of this process.

Add the sugar and orange zest mixture, butter, and brown sugar to the bowl of a stand mixer. Fit the mixer with a paddle attachment. Mix on medium-low speed until the butter is light and airy, about 3 minutes. Scrape down the sides of the bowl.

Use a large #16 ice cream/cookie scoop to divide the dough into 8 portions of about 90 grams each. If you don’t have a cookie scoop, use a 1/3 cup measuring cup. Transfer the divided dough to a plate.

Use a greased silicone spatula to divide the nian gao filling into 8 portions of about 35 grams each. If you do not have a scale, use greased measuring spoons to measure 2 tablespoons of nian gao for each portion. Transfer the nian gao pieces to a greased plate. You do not need to roll the nian gao into balls.

Take a piece of the cookie dough and shape it into a large bowl. Place a piece of nian gao inside and wrap it with the cookie dough. The cookie dough exterior may split open at certain places, especially areas where there’s a large chocolate chunk. Just use your fingers to pinch the dough together. Roll the cookie dough into a ball. If you reserved any chocolate chunks, press 1 to 2 pieces of chocolate on a rolled up ball of dough.

Transfer the cookie sheets to the oven and bake for 7 minutes. Rotate the pan halfway through baking and switch the position of the sheet pans for even baking. Bake the cookies for another 7 to 8 minutes, until the bottom edges start to turn golden.

Sprinkle a small pinch of flaky salt over the cookies, if desired. Let the cookies cool on the sheet for 10 minutes before transferring to a cooling rack to cool. The center of the cookies will be incredibly soft and stretchy if you eat them in the next 30 minutes. The centers will solidify slightly into a mochi-like texture once they cool. Store the cookies in an airtight container for up to 3 days. If you want to reheat the cookies to soften the center, bake them at 350ºF (175ºC) for 4 to 5 minutes.