01 - Preheat oven to 350°F (175°C) and line a baking sheet with parchment paper.
02 - In a large bowl, beat softened butter and granulated sugar until light and fluffy, approximately 2-3 minutes.
03 - Mix in egg yolk and vanilla extract until fully incorporated.
04 - Gradually blend in flour and salt, mixing until just combined. Avoid overmixing to prevent tough cookies.
05 - Roll dough into 1-inch balls and arrange on prepared baking sheet, spacing 2 inches apart.
06 - Using thumb or the back of a spoon, gently press a well into the center of each dough ball.
07 - Spoon approximately 1/2 teaspoon of lemon curd into each indentation.
08 - Bake for 10-12 minutes until edges begin turning golden brown while centers remain slightly soft.
09 - Let cookies rest on baking sheet for 5 minutes before transferring to wire rack. Dust with powdered sugar once completely cooled, if desired.