Coniferous forest made of cookies

Ingredients:

Cookie

• 4 and 3/4 cups of premium flour, plus extra for working with the dough
• 1/4 teaspoon of baking soda
• 1/4 teaspoon fine salt
• 2 tsp vanilla extract
• 3 large eggs
• 330 g unsalted butter, room temperature
• 1 cup granulated sugar
• 0.5 cup powdered sugar
• Special equipment: Christmas tree-shaped cookie cutters (10 cm, 15 cm, and 20 cm); 2 pastry bags; 2 small round tips No. 4

Royal icing

• 450 g powdered sugar + more as needed
• 2 tbsp. dry egg white
• 1 tsp vanilla extract
• Green gel food coloring
• White sprinkles, for decoration

Preparation:

1. Bake some cookies:
   
   In a medium bowl, whisk together the flour, baking soda, and salt. In a small bowl, whisk together the vanilla extract and 2 eggs. In a large bowl, beat the butter, sugar, and powdered sugar with a mixer on low speed. Once incorporated, increase the speed to medium and beat, scraping down the sides of the bowl as needed, for about 3 minutes.
2. Reduce mixer speed to low, slowly pour in the egg mixture, and mix. Add the flour mixture in three additions, increasing the speed as the dough thickens to avoid stalling the mixer. Scrape down the sides of the bowl as needed. Once all the flour is incorporated, increase mixer speed to medium-high and beat until the dough is very smooth, about 5 minutes.
3. Remove the dough from the bowl onto a clean work surface. Divide into two pieces. Form each piece into a flat square and wrap in plastic wrap. Refrigerate for at least 3 hours or overnight.
   
   
   When measuring flour, spoon it into a dry measuring cup and remove any excess. Scooping flour directly from the bag with a measuring cup will compact it, resulting in dry baked goods.
4. Position oven racks in the upper and lower thirds of the oven and preheat to 350°F (175°C). Line 3 baking sheets with parchment paper.
5. Cut out and bake the Christmas trees:
   
   Flour your work surface and roll out the dough to a thickness of about 0.5 cm. Refrigerate the other half of the dough. Cut out Christmas trees from the dough using cookie cutters of various sizes and cut out the trunks from the dough. For each 3D tree, you'll need two cut-out trees of the same size, so cut out the shapes in pairs.
   
   Culinary adviceIf you don't have a Christmas tree cookie cutter, you can make a stencil. Using a ruler, draw the outline of a tree on paper. Cut it out and use it as a stencil, cutting out shapes from the dough with a small knife.
6. For our forest, we cut out 10 cm, 15 cm, and 20 cm fir trees. Place the trees on prepared baking sheets and refrigerate while you roll out the remaining dough and cut out the shapes. Mix the scraps from the two dough portions. Chill again, roll out, and cut out more trees; you should have 8-10 pairs of trees, depending on the size of your cutouts.
7. Place the dough figures in the freezer for at least 30 minutes.
8. Place the cookies on the baking sheets so that the pairs are next to each other. Using a sharp knife, cut a 1-cm-wide slit on one cookie in each pair, starting from the bottom and ending just above the halfway point. Cut the same slit on the second cookie in each pair, but from the top of the tree down to just below the halfway point. Assemble the cookies after baking.
9. Return the cookies to the freezer for another 30 minutes.
10. In a small bowl, whisk the remaining egg with 2 tablespoons of water. Brush the cookies with a thin layer of the egg mixture before baking.
11. Bake the cookies, rotating the baking sheets halfway through, until golden brown and set on top, 15 to 18 minutes. Cool completely on the baking sheets on a wire rack, about 30 minutes.
12. Meanwhile, prepare the royal icing.:
    
    In a large bowl, combine the powdered sugar, dry egg white, and vanilla extract. Add 5 tablespoons of water and beat with an electric mixer on medium-high speed until stiff, glossy peaks form, about 2 minutes, adding up to 1 tablespoon of water if necessary. Transfer one-third of the royal icing to a pastry bag fitted with a small round tip #4.
13. Tint the remaining frosting with green food coloring, adding one drop at a time, until it reaches the color of the pine needles. If the frosting is still too strong, add 1-2 teaspoons of water. Fill a second pastry bag fitted with another small round tip #4 with green frosting.
14. Using a sharp knife, scrape the edges of the cookies to make them smooth and flat, paying particular attention to the bottom edges of the trees (to ensure they stay in place) and the edges of the slits. Assemble the trees, matching two trees in each pair. If necessary, scrape the edges of the slits to make the cookies easier to insert, then disassemble the trees and place the cookies on a flat surface. Don't worry if the cookies break; the pieces can be glued together with green royal icing.
15. Color the Christmas trees:
    
    Decorate each cookie with green icing, leaving a stripe in the center uncovered; this is where the cookies will join. You can pipe the icing in a zigzag pattern. Sprinkle with white sprinkles while the icing is still wet. Let it harden completely, about 30-45 minutes.