Using an electric mixer, whip the butter and sugar together until it is light and fluffy, about 1 minute. Using a spoon, stir in the salt, rosemary and the flour ¼ cup (30g) at a time until all is added. Gather the dough into a ball, place in a container or bowl and chill for at least 1 hour. 

Heat your oven to 300°F (148°C). Line a cookie sheet with parchment paper. Roll out the cookie dough on a lightly flour surface. The dough should be evenly rolled, 1/4” thick (.5cm). Prick the rolled dough evenly with a fork. Cut the dough into small bars, approximately 1”x 3” (2.5cm x 7.6cm). Place the bars on the parchment lined cookie sheet and bake in the preheated oven for 20-25 minutes, until the cookies are light golden brown. Cool the cookies on a cooling rack. Store in an airtight container. 

Makes about 5 dozen cookies