Cookies "Valentine's Letters"

Ingredients:

Cookie dough

• 220 g softened butter
• 1 cup granulated sugar
• 1 large egg, lightly beaten
• 1 teaspoon vanilla extract
• 3 cups flour, plus extra for dusting
• A pinch of salt

Royal icing

• 4 cups powdered sugar, sifted, more if needed
• 3 tbsp. dry egg white
• 6-7 tbsp warm water, plus extra for dilution
• 1/2 tsp lemon essence
• Red, pink and black gel food coloring
• 3/4 cup heart-shaped sprinkles
• Black food marker
• Special equipment: Rectangular cookie cutter (10 cm); Rectangular cookie cutter (5 cm); 4 pastry bags or decorating bottles; Cellophane bags; Baker's twine

Preparation:

1. For the test. In the bowl of a stand mixer fitted with the paddle attachment, cream together the butter and granulated sugar. Add the egg and vanilla extract. Mix again on low speed, stopping occasionally to scrape down the sides.
2. Add flour and salt. Mix on low speed until a dough forms and no streaks of butter remain in the bowl. The dough will be firm and should not stick.
3. Line two baking sheets with parchment paper.
4. Divide the dough into two pieces. Place one piece on a lightly floured work surface and roll it out to a thickness of just over 0.6 cm. Using a 10 cm rectangular cookie cutter, cut out 15 cookies. Place 7 on one baking sheet and 8 on the other. Using a 5 cm cookie cutter, cut out the centers of 5 cookies. Chill the cut-out dough for 20 minutes. Wrap the remaining dough in plastic wrap and refrigerate until ready to use.
5. Preheat oven to 180°C.
6. Bake the cookies for 12-15 minutes, or until golden brown around the edges. Transfer them to a wire rack to cool completely. Let the baking sheets cool, then reline with parchment paper. Repeat the rolling, cutting, cooling, and baking process with the remaining half of the dough. Makes 30 cookies, 10 of which will have the cores cut out.
7. For royal icing. In the bowl of a stand mixer fitted with a whisk attachment, combine the powdered sugar and egg whites on low speed. Add the water and beat on medium-high speed for 3-5 minutes until stiff peaks form. Add the lemon zest and beat on low speed, mixing thoroughly. Divide the frosting among three bowls, adding 1/4 cup to each. Cover the remaining frosting in the bowl with a damp paper towel to prevent it from drying out. Tint the frosting in one bowl red, in another pink, and in the third black (the frosting in the stand mixer bowl will remain white). Add a few drops of water to all four portions of frosting to thin the consistency. (Check the consistency by running a spoon down the center of the icing; ideally, the mark should disappear completely within 10 seconds. If necessary, thin with water or add powdered sugar to thicken.) Place each portion of icing into individual pastry bags or decorating bottles.
8. Cut a sheet of parchment paper into 10 small strips, approximately 10 x 5 cm. On one side of the strip, write love messages, such as "I love you more than cookies!" and "You are adorable!"
9. Place 10 whole cookies on a parchment-lined work surface. Pipe white icing along the outer edge of each cookie. Place the center-less cookies on top. Fill each with 1 tablespoon of heart-shaped sprinkles. Pipe white icing along the top outer edge of each cookie. Fold the love notes with the written side facing inward to prevent the ink from touching the cookies. Place the folded note into each coreless cookie and top with a whole cookie.
10. Pipe white icing onto the outer edges of the top cookies, filling them all the way around so that the top of the cookies is covered. If there are any gaps, use a toothpick to push the icing into them. Let the cookies rest for about 3 hours until the surface is smooth and dry.
11. Once the top layer is dry, pipe an envelope outline on half of the cookies (5) with white icing. Scrape off the top of the triangle with a toothpick to create space for the decorative stamp. Using red icing, pipe a small stamp in the center of each envelope. Using white icing, pipe lines from both sides of the envelope flap to the bottom corners—this will be the inside of the envelope. Using pink icing, draw a few hearts on the envelopes. Using an edible marker, draw a dotted line across the center of the cookie and write "open here."
12. On the remaining cookies, use black icing to draw three identical horizontal lines down the center for the address. Use red icing to draw a heart in the upper right corner of the cookie for the postage stamp. To the left of the heart, use a black edible marker to draw wavy lines. Decorate the cookies with kissing symbols ("XO") in the upper left corner and write the recipient's name above the center lines. Use the remaining black icing to draw semicircular postmarks on the sides.
13. Let the cookies rest for about 3 hours. Place the finished cookies in plastic bags and tie with baker's twine. If desired, include a note asking the recipient to open the cookies so they know the hidden messages.