01 -
Heat oven to 350°F. Line trays with paper.
02 -
Beat butter, vanilla and sugar until fluffy. Stir in flour and cornstarch in three batches.
03 -
Roll tablespoons of dough into balls. Press with fork to 1cm thick.
04 -
Bake 15 minutes, switching trays halfway. Cool completely.
05 -
Beat butter until fluffy. Add sugar in batches, then lemon zest and juice.
06 -
Pipe filling on half the cookies, sandwich with remaining cookies. Chill 1 hour.