• Line baking sheets with parchment paper or leave them ungreased.
• In a medium bowl, cream together the butter and sugar until light and smooth.
  
• Add the egg yolks one at a time, mixing well after each addition. Stir in the almond extract.
• Add the flour and salt, then mix by hand with a wooden spoon until a soft dough forms. It may seem very dry at first, but keep working the butter through, and it will come together.
  

Shape & Chill

• Shape the dough into a log about 12 inches (30 cm) long.
  
• Wrap tightly in parchment or plastic wrap and refrigerate for 15-30 minutes.

Slice & Bake

• Preheat the oven to 375°F (190°C).
• For 16 cookies: slice the log into 16 rounds, each about 3/4 inch (1.8–2 cm) thick. This is the size shown in the photos.

  For 24 cookies: slice the log into 24 thinner rounds, each about 1/2 inch (1.25 cm) thick.
  
• Using your hands, roll each round into a ball, and then flatten slightly into a rounded disc. This step is essential for shaping the cookies.
  
• Press the disc into the sugar to coat one side, then place it on the sheet pan sugared side up.
  
• Using your thumb or a small round tool, gently press an indentation into the center of each cookie (I use a clean wine bottle cork). See the notes below for cookies with hearts.
  
• Fill each indentation with about ½ teaspoon fruit preserves.
  
• Bake for 10–12 minutes for the small cookies (24 batch) and 12-15 minutes for the larger size (16 batch), until the cookies are set and just beginning to turn golden on the bottom.
  
• Let cool on the baking sheet for 15 minutes, then transfer carefully to a wire rack to cool completely. They are fragile until completely cooled.