Lemony Slice-and-bakes

A big thanks to my friend Sally North who posted the picture on Facebook which prompted me to ask for the recipe. Makes about 50

To keep the rolled dough's cylindirical shape, chill it or freeze it inside empty cardboard paper towel tube.

Dough:
2.1/2 cups all-purpose flour
1/2 tsp kosher salt
1 cup (2 sticks) unsalted butter, room temperature
3/4 cup sugar
2 tbsp finely grated lemon zest
1 tbsp vanilla extract
4 large egg yolks

Icing:
1.1/4 cups powdered sugar
2 tbsps (or more) fresh lemon juice
Food colouring (optional)
Sanding sugar (optional)

Steps:
1. Whisk flour and salt in a bowl. Use electric mixer to beat butter, lemon zest and and vanilla in a bigger another bowl, occasional scraping down sides until light and fluffy. Add in yolks, beat just to blend. Reduce speed to low, add flour mixture in parts to blend. Part dough in half, and roll each half into 10 inch-long log and 1/3/4 inch in diameter. Chill until firm, about 1 hour. Can be made 2 days ahead, and keep chilled.

Using a sharp knife, cut dough into 1/4 inch-thick rounds. Line on baking sheet, spacing 1 inch apart. 350F, 16-18 mins. Cool on wire racks completely.

2. For icing; whisk sugar and lemon juice (and food colouring). Spread or drizzle icing on cookies as desired. Let sit for 10 minutes. Store in airtight container.