This recipe can be easily doubled if desired. I will often double it, and then divide the dough into four equal portions and make the different shortbread cookie variations (which you can find elsewhere on this site) for a nice variety for the holidays. —Food52
Pre-heat oven to 350 F degrees. Line a baking sheet with parchment paper. In the bowl of a stand mixer fitted with the paddle attachment, cream together butter and powdered sugar until pale and fluffy. Whisk together all purpose flour, cocoa powder, rice flour and salt until combined. Add in two additions to the butter mixture and beat on low until combined.
Divide your dough into two parts. Shape each part into a disc and wrap with plastic wrap. Allow the dough to chill for 30 minutes.
Remove dough from fridge and allow to warm up for five minutes at room temperature. Lightly flour a dry, cool work surface and use a rolling pin to roll your chilled dough out to ¼ inch thickness.
Take a tree cookie cutter or whatever shape you like, and cut out your shapes. Place the cookie cut outs onto a parchment lined baking sheet, leaving 1 inch in between each cookie.
Bake at 350F for 9-10 minutes. Remove from the oven and allow to cool completely.
Melt a bowl of your favourite dark chocolate and simply drizzle over top of the trees or dip half the cookie and place on a piece of parchment paper to cool. Sprinkle with chopped nuts if desired.
Allow the chocolate to set for thirty minutes at room temperature before serving or place the slices in the fridge for a few minutes to speed up the process.