Walnut cookies
Cantonese walnut cookies, also called hap tou sou, are crisp, crumbly cookies you will often find in Chinese bakeries and on the tea table at Lunar New Year. They use vegetable oil instead of butter along with baker's ammonia, so they puff up light, crack naturally on top and crumble in your mouth. The nutty richness of toasted walnuts mingles with a touch of brown sugar for a rustic, unforgettable aroma.
- Difficulty
- Very easy
- Prep
- 25 min
- Cook
- 18 min
- Rising or chilling
- 15 min
- Total time
- 58 min
- Method
- Oven-baked
Ingredients
Walnut cookie dough
Walnut topping and yolk glaze
Instructions
Step 1
Spread 100 g walnuts for the dough and 45 g walnuts for decorating on a tray, toast them in the oven at 160°C for about 8 to 10 minutes, then let them cool. Toasting removes the bitterness of the papery skins and deepens the nuts' flavor. They are ready when they turn golden brown, snap crisply and smell rich and nutty.
Step 2
Put the walnuts for the dough in a food processor with a little of the flour taken from the weighed amount and pulse briefly a few times until the nuts look like coarse sand. The flour keeps the nuts from turning into an oily butter. You are done when the crumbs are even and still loose.
Step 3
In a large bowl, whisk 50 g eggs with 70 g brown sugar, 50 g powdered sugar and 120 g vegetable oil for about a minute. The oil makes the cookies crumbly and keeps them from hardening as they sit. The mixture is ready when it is slightly thick, even and the sugar has almost dissolved.
Step 4
Sift the remaining 250 g all-purpose flour with 2 g baking soda, 2 g baker's ammonia and 2 g salt into the bowl, add the ground walnuts and gently sweep everything together into a mass with a flat spatula. Do not knead, so the cookies stay as loose and crumbly as the traditional kind. The dough is ready when it is soft, a little oily and can be pressed together into a ball.
Step 5
Cover the bowl and let the dough rest at room temperature for about fifteen minutes; meanwhile, heat the oven to 175°C. Resting lets the flour absorb the oil and egg, so the balls you roll will be smoother. The dough is ready when it is less sticky and slightly pliable.
Step 6
Roll the dough into balls about the size of a jujube, set them four centimeters apart on a lined tray, flatten them slightly, then brush with 18 g beaten egg yolks and press a piece of walnut into the center of each. The yolk gives a glossy golden-brown finish and holds the nut firmly on top. You are done when every cookie has a shiny top with a walnut piece sitting neatly in the middle.
Step 7
Bake at 175°C for 15 to 18 minutes. The baker's ammonia gives off a sharp smell at first, but it bakes off completely in the oven, leaving the cookies light and airy. They are done when the tops show fine crackles, the color is golden brown and the ammonia smell is gone.
Step 8
Leave the cookies on the tray for about five minutes, then move them to a rack to cool completely. Hot cookies are very crumbly and only firm up once cool. They are ready when they snap crisply, are airy inside and smell of walnuts.
Equipment
- Oven
- Mixing bowl
- Whisk
- Spatula
- Sieve
- Kitchen scale
- Food processor
- Baking sheet
- Parchment paper
- Pastry brush
- Wire cooling rack
Tips
- If you do not have baker's ammonia, use the same amount of baking powder instead; the cookies will still be delicious, just a little less crisp and airy.
- Using peanut oil instead of regular vegetable oil gives the cookies a deeper aroma, just like the ones from Chinese bakeries.
- Bake in a well-ventilated kitchen and open the oven door carefully, because the baker's ammonia smells quite pungent for the first few minutes.
Storage
Once completely cool, the cookies stay crisp in an airtight container at room temperature for about two weeks. If they soften, crisp them up in a 150°C oven for about five minutes and let them cool.
Common problems and how to fix them
- The cookies still smell of ammonia after baking.
- The balls were too thick or the cookies were not baked long enough for the gas to escape. Flatten the dough more and bake a few minutes longer at a lower temperature.
- The cookies leak oil and turn soft.
- The walnuts were ground too long into nut butter or there was too much oil. Grind the nuts with a little flour and use only short pulses.
This recipe is based on the common ratios for this bake and is written entirely in our own words.
