Chocolate Sugar Cookies

Ingredients:

• 1 and 3/4 cups of premium flour + extra for working with the dough
• 0.5 cup cocoa powder
• 3/4 tsp baking soda
• 1/4 tsp baking powder
• 0.5 tsp salt
• 220 g unsalted butter, room temperature
• 1 and 3/4 cups granulated sugar
• 1 large egg
• 1 tsp vanilla extract
• 2 cups powdered sugar
• 2 tbsp. dry egg white
• Coarse sugar for decoration (optional)

Preparation:

1. In a medium bowl, combine the flour, cocoa powder, baking soda, baking powder, and salt. In a large bowl, beat the butter and sugar with a mixer on medium-high speed until light and fluffy, about 5 minutes. Add the egg and vanilla extract; beat until creamy, about 2 minutes more. Reduce the mixer speed to low; gradually add the flour mixture and mix until smooth, about 2 minutes more.
2. Divide the dough in half and place on 2 pieces of plastic wrap; form into disks. Wrap and refrigerate until firm, at least 1 hour.
3. Roll the dough out between floured sheets of parchment paper to a thickness of about 0.5 cm. Refrigerate for another 2 hours.
4. Position racks in the upper and lower thirds of the oven; preheat oven to 350°F (175°C). Spray 2 baking sheets with cooking spray.
5. Cut out shapes from the dough; gather the scraps and roll out again. Cut out more shapes. Place the cookies on the prepared baking sheets, spacing them 2 inches (5 cm) apart. Bake, rotating the baking sheets halfway through, until set, about 12 minutes. Let cool on the baking sheets for 5 minutes, then transfer to a wire rack to cool completely.
6. Prepare the glaze:
   
   In a bowl, beat the powdered sugar, egg white powder, and 3-4 tablespoons of water with a mixer on high speed until smooth and thick. Transfer the icing to a zip-lock bag and snip off a small corner. Pipe the icing onto the cookies and sprinkle with coarse sugar. Let it sit for 30 minutes.