- With the rack in the middle position, preheat the oven to 190 °C (375 °F). Line a baking sheet with parchment paper.
- In a bowl, combine the flour, baking soda, and salt. Set aside.
- In another bowl, cream the butter with the brown sugar, orange zest, and orange liqueur. Add the egg and beat until incorporated. With a wooden spoon, stir in the dry ingredients and chocolate.
- For each cookie, form a 30 ml (2 tablespoons) ball of dough with floured hands. Place nine cookies per baking sheet. Bake for 8 to 9 minutes or until they start to brown slightly around the edges.
- Cool completely.