Learn how to make chocolate pinwheel cookies with this easy recipe. You only have to make one vanilla dough, which you split into two to flavour half with chocolate!
In a bowl, whisk together the flour and salt. Set aside.
In the bowl of an electric fitted with the paddle attachment, beat together the butter with the sugar until fluffy. Add the eggs, one at a time, beating between additions and scraping down the sides of the bowl as needed. Mix in the vanilla. The mixture should be smooth and light.
Add the flour and stir it in on low. Mix until just combined.
Remove half oof the dough (roughly 450 grams or 1 lb of dough). To the dough left behind in the mixer bowl, add the cocoa powder and stir it in.
Pat each dough into a disk, wrap in plastic wrap and chill at least 1 hour.
Divide each disk into four pieces. Store extra pieces of dough in the fridge while you work.
Roll one piece of chocolate dough to a 6x7-inch rectangle between pieces of wax paper.
Roll one piece of vanilla dough to a 6x6 square between pieces of wax paper.
Chill both rolled doughs for 10 minutes in the freezer.
Remove wax paper from both sheets of dough. Place the vanilla dough over the chocolate dough, leaving a half inch border on top and on bottom. Press together with a cookie sheet to help them adhere (or using a gently using a rolling pin). If the dough feels at all soft, chill it again.
Roll the dough tightly into a cylinder to form a pinwheel using the paper to help keep the roll tight. Roll the log back and forth to seal the layers together and form a perfect cylinder.
Repeat with remaining doughs to form 4 logs of pinwheel dough. Wrap the logs in plastic wrap and chill overnight.
Preheat the oven to 350ºF (175 °C). Line two sheet pans with parchment paper.
Unwrap a log of pinwheel cookie dough and trim the ends off. Slice cookies to about ⅛–¼ inch (3–6 mm). Place 1 inch apart on parchment-lined baking sheets. Bake one sheet at a time until cookies look set and dry, for approximately 13 minutes.
Notes
Use Dutch-processed cocoa powder, though natural or black cocoa will also work. The resulting chocolate cookie dough taste, colour, and texture may vary depending on the type and brand of cocoa you use.
Sift the cocoa powder to remove any lumps.
The cookie dough becomes very soft if it is warm. Chill the dough thoroughly to be cold and firm before rolling them out. Once rolled, chill them again before layering them. And then chill them again after layering them. The pinwheel spiral may be distorted or deformed if the dough is not cold enough.
Roll the dough between layers of parchment paper or wax paper. Don't use flour, as the flour may prevent the chocolate and vanilla dough from adhering together when you create the pinwheel.
The thicker you slice the cookies, the fewer you will get and the longer they may take to bake. The thinner you slice the dough, the more cookies you will make, and they will take less time to bake.
For peppermint-flavoured pinwheel cookies, add 2.5 mL (½ teaspoon) peppermint extract.
For almond-flavoured pinwheel cookies, add 2.5 mL (½ teaspoon) almond extract.
If you want to use food colouring, use gel food colours to dye the vanilla dough red or green, for example.