This is the chocolate variation for my shortbread cookies series (visit my blog posts, Espresso Shortbread Cookies and Vanilla Shortbread Cookies, for other flavours). When I posted the cookie picture on my facebook page, a reader asked me how I created those beautiful little cracks on the surface. The secret lies in the aeration of butter. You will need to whip the butter a little bit longer until the colour starts to lighten a bit. When more air is trapped within, the cookie dough will expand more in the oven when heated, resulting in tiny cracks. If you want bigger, more pronounced cracks, you may even add in a dash of baking soda when mixing the dough. I will show you pictures at the end of the post for you to see the difference. You don’t want to use these strategies when making cutout cookies though. For cutout cookies, you will definitely want to keep the whipping to a minimum so the cookies won’t spread out nor expand in the oven since cookies will crack and lose their shapes in this way. I’ve shared some of my tips for making tender cookies and maintaining cookie shapes in my blog posts such as Vanilla Bean Cutout Cookies, Chocolate Cutout Cookies (Soft and Tender), Espresso Cutout Cookies. The mixing method and technique I used are very different from the recipe I am sharing below. If you have time, please go and take a look.
Chocolate Shortbread Cookies
150 g salted butter (slightly softened)
60 g icing sugar
12 g unsweetened cocoa powder (use 17 g for a more intense flavour)
110 g all purpose flour
80 g cornstarch
含鹽牛油 (少許回溫) 150克
In the bowl of a stand mixer fitted with the paddle attachment or with an electric mixer, beat butter on low speed until smooth. Add icing sugar and cocoa powder and mix briefly on low speed, then switch to medium speed and beat until mixture has lightened slightly. Scape down the sides of the bowl as needed
In a large bowl, combine and sift together the flour and cornstarch. Add flour mixture to butter mixture in two additions and mix on low speed until mostly incorporated. Switch to a spatula and finish mixing by hand while scraping the sides and bottom of the bowl to form a soft and pliable dough that is slightly sticky. Do not over-mix. Wrap the dough with plastic wrap and let rest at room temperature for 30 minutes (the dough will become less sticky by then).
Preheat the oven to 325℉/160℃ with fan. Divide the dough evenly into 30 portions, 13 to 14 g each. Roll each into a ball then arrange the dough balls onto a parchment paper lined baking sheet. Gently flatten the dough balls into thick discs with your palm. The dough will spread out a little in the oven so make sure to leave enough space between them.
Bake for 25 minutes. Remove from the oven and cool cookies completely on the cookie sheet on a cooling rack. For better texture, store cooled cookies in an airtight container and allow the cookies to rest and develop flavour for at least half a day before consuming.
For more pronounced cracks, add 1/8 teaspoon of baking soda (top picture). The ones on top were made with more cocoa powder (17 g) but my kids said the cookies were a bit on the bitter side for them.