Step 1

Make the dough: In a large mixing bowl, combine the flour, canola oil, golden syrup, and alkaline water. Using a flexible spatula, mix to form a shaggy dough, then knead with your hands to form a smooth, cohesive dough. Form the dough into a thick disc, wrap in plastic, and allow it to rest at room temperature for 45 minutes.

Step 2

Preheat the oven to 350ºF and line a large rimmed baking sheet with parchment paper.

Step 3

Make the filling: In the bowl of a food processor, pulse the pistachios until coarsely ground. Add the honey, coconut oil, cornstarch, and salt and continue to pulse a few more times. The filling should be a little crumbly but stick together when pressed. (Avoid overprocessing, so you don’t end up with pistachio butter.) Divide the filling into 12 equal portions (for accuracy, weigh with a digital scale if you have one) and shape each piece into a ball.

Step 4

Divide the disc of dough into 12 equal pieces with a bench scraper (for accuracy, use a digital scale). Roll each piece into a smooth ball. Working with one piece at a time, flatten a dough ball with your palm and roll out into a 4-inch round. Continue to lightly dust with flour if sticking. Use a bench scraper to help lift up the dough.

Step 5

Center a ball of filling on the round. Bring the edges of the dough up around the filling. The dough won’t initially cover all of the filling; just pinch it together until it completely wraps the filling. Pinch together any cracks that form and roll into a smooth ball.

Step 6

As you form the balls, arrange them on the prepared baking sheet, spacing at least 2 inches apart. Lightly dust the mooncake mold with flour. Place a ball in the mold and press the plunger down to apply pressure, but take care not to press too hard. Gently release from the mold and return to the baking sheet. Repeat with remaining dough and filling to form all 12 mooncakes.

Step 7

Bake mooncakes until the edges are lightly golden brown, 9 to 11 minutes. Remove the sheet from the oven and allow the cakes to cool on the sheet for 10 minutes. In a small bowl, mix together the egg and tap water. With a pastry brush, lightly coat the mooncakes with egg wash. Return to the oven and bake until deep golden brown, 10 minutes.

Step 8

Transfer the baking sheet to a wire rack and allow the mooncakes to completely cool on the sheet. Before serving, store mooncakes in an airtight container (a resealable bag works great) at room temperature for 1 to 2 days to allow the exterior dough to soften.