Place all ingredients in a bowl and mix well to combine. Transfer the dough to a lightly floured surface and divide in half. Shape and roll each dough half into a roll that is 1 1/2 inches in diameter. Wrap each roll in plastic wrap and chill 2 hours. Place the oven rack in the middle of the oven; preheat the oven to 300 degrees F. Line 2 baking sheets with parchment paper. Unwrap one of the rolls and cut into 1/4” thick slices. Arrange the slices on one of the baking sheets, spacing them 2” apart. Bake for 18 to 20 minutes, or until a light golden brown. Remove from the oven and cool the shortbread to room temperature on a baking rack. Repeat these steps with the remaining roll of unbaked shortbread. Store the shortbread in an airtight container until ready to serve.