01 - Preheat oven to 350°F. Line two baking sheets with parchment paper.
02 - In a large bowl, cream softened butter and granulated sugar until light and fluffy.
03 - Beat in egg yolk and vanilla extract until fully incorporated.
04 - Add salt and flour, mixing until just combined. Avoid overmixing.
05 - Scoop tablespoon-sized portions, roll into balls, and place on prepared baking sheets 2 inches apart.
06 - Press thumb or back of small spoon into center of each dough ball to form a well.
07 - Fill each indentation with approximately 1/2 teaspoon of flower jam.
08 - Bake 12–15 minutes until edges are just turning golden.
09 - Let cookies rest on baking sheets 5 minutes, then transfer to wire rack to cool fully.
10 - Dust with powdered sugar once completely cooled.