I made these for my quilting group the other week. Since they went down rather well, I thought I will share the recipe here. They taste wonderful right from the fridge or even the freezer, especially on a hot summer day.
125g (1 stick) butter, softened
130 g (2/3 cup) sugar
1 egg yolk
1 tbsp grated lemon zest
1 tsp vanilla
135g (1 cup plus 2 tbsp) flour
1/2 tsp salt (I use less)
75 g (3/4 cup) powdered sugar
1 tbsp plus 1 tsp lemon juice
Cream together butter and sugar until light and fluffy. Beat in egg yolk, zest and vanilla. Then gently beat in flour and salt until dough holds together. Press into a ball and divide in two. Roll into two small logs, wrap into cling film and chill.
To bake, preheat oven to 190 degrees C (375 degrees F). Lightly grease two baking sheets or line with parchment paper. Cut each log across width into 1 cm (3/8 inch) slices. Arrange slices on baking sheet at least 2 to 3 cm (1 inch) apart. Bake for about 10 minutes, until edges are golden and centers set. Transfer to racks to cool.
For glaze; in a small bowl whisk together sugar and lemon juice until smooth and thick enough to spread. Thin with a few drops lemon juice or thicken with sugar if needed. Hold each biscuit along the edge and spread a thin layer of glaze with a small spatula.