Diamond cookies are French sable cookies. They are buttery and crispy with sugar nicely coated around, appears to have been rolled in diamonds. These cookies should not be eaten warm. They need to cool completely so that their texture will be crispy.
60g unsalted butter, softened
35g confectioner’s sugar, sifted
1/4 teaspoon sea salt
10ml whipping cream
85g all-purpose flour, sifted (for chocolate flavor, use 75g all-purpose flour & 10g cocoa powder)
egg white for brushing & coarse sugar for decorating
How to make
In a large bowl, mix the butter in low speed until smooth and creamy, about a minute.
Add the confectioner’s sugar and mix until smooth about a minute. Scrape the bowl as needed.
Add salt, whipping cream, flour, still on low speed and mix until blended (the dough should be soft).
Turn the dough out onto the table and roll util it becomes a 30cm log. Wrap in plastic wrap and refrigerate for at least 2 hours or 1-1/2 hours in the freezer until the center of the dough is completely frozen.
Brush the log with egg white and roll it in the coarse sugar until evenly coated. Use a knife and cut the dough into 1cm thick rounds. Put them on the baking sheets and use your thumb to slightly press the center of the cookies.
Bake the cookies at 160C for 18~22 minutes. Let cool on the baking sheets for 5 minutes, then carefully transfer to a cooling rack and let cool completely before serving.
You can make the unbaked logs in advance. Just wrap in plastic and keep in the freezer for up to 2 months. Let them sit in room temperature for about 10 minutes before cutting and baking. No need to fully defrost them.