01 -
Beat softened butter and powdered sugar until smooth and creamy. Mix in egg yolk, vanilla and salt.
02 -
Add flour and mix just until a soft dough forms. Cover and chill for 30 minutes. Heat the oven to 180°C / 350°F and line two baking sheets with parchment.
03 -
Divide dough into 20 equal pieces and roll into balls. Space them about 5 cm / 2 inches apart on the sheets.
04 -
Press a small well into each ball with a rounded measuring spoon. Smooth any cracked edges. Fill each well with about 1 teaspoon jam; do not mound it above the rim.
05 -
Bake one sheet at a time for 12–15 minutes until edges are lightly golden and the bases are set. The centers will remain pale.
06 -
Cool on the sheet for 10 minutes, then move to a rack for another 10 minutes. Jam stays hot longer than the cookie, so let it cool before tasting.
07 -
Keep fully cooled cookies in an airtight container for up to three days in a cool room, separating layers with parchment. Freeze without stacking loosely for longer storage, then pack once firm.