Prep time: 10 minutes
Cook time: 15 minutes
- 3/4 cup (165 grams) unsalted butter, cubed and softened to room temperature
- 1 1/4 cups (180 grams) all-purpose flour
- 1/2 cup (70 grams) custard powder, preferably Bird's (see author's notes)
- 1/2 cup plus 1 tablespoon (70 grams) confectioners' sugar
- 1/2 teaspoon instant espresso powder or instant coffee
- 2 tablespoons whole milk
- 1/4 teaspoon vanilla extract
- 5 1/4 ounces (150 grams) bittersweet chocolate chips (or chopped bittersweet chocolate)
- Flaky salt, for sprinkling (optional)
- Add the butter to the bowl of a stand mixer and beat with the paddle attachment until it turns pale and fluffy, about 3 minutes.
- Remove the bowl from the mixer and, using a fine-mesh sieve, sift the flour, custard powder, confectioners' sugar, and espresso powder on top of the butter.
- Return to the mixer and mix on low speed until the mixture begins to resemble cookie crumbs. Scrape the sides of the bowl down with a bowl scraper or rubber spatula.
- Add the milk and vanilla and mix on medium speed until you get a smooth dough, about 1 minute.
- Add the chocolate chips and mix on medium speed for about 30 seconds until evenly distributed. Scrape down the sides of the bowl and transfer the dough to a sheet of parchment paper or a container.
- Divide the dough by weight into 20 equal pieces. Shape each into a 2-inch/5-centimeter circular disk. The cookie dough can be frozen for up to 1 month, if wrapped with plastic wrap and separated by parchment paper.
- To bake the cookies, place two wire racks in the middle of the oven and heat to 350°F (180°C). Line two baking sheets with parchment paper and add the cookies, each about an inch (2 1/2 centimeters) apart. The cookies will not spread during baking. Sprinkle with flaky salt if you'd like (there's salt in the custard powder so I personally skip this).
- Bake for 15 to 25 minutes, until the edges start to turn golden brown, swapping the baking sheets between the racks and rotating them halfway through during baking.
- Let the cookies cool on the baking sheets for about 5 minutes, then carefully transfer them to a wire rack to cool completely. Store the cooled cookies in an airtight container for up to 1 week.