Brown Sugar Sandwich Cookie Recipe

INGREDIENTS

• 2 1/2 cups whole wheat pastry flour
• 1 teaspoon baking powder
• scant 1 teaspoon salt
• 2 tablespoons + 1 teaspoon poppy seeds
• 6 ounces (1 1/2 sticks) unsalted butter, room temperature
• 2/3 cup good-quality brown sugar / natural cane sugar
• 2 large egg yolks
• 1 tablespoon vanilla extract
• 2-3 tablespoons milk
• 1 tablespoon big flaky sea salt (optional)
• 1 tablespoon turbinado sugar (optional)
• 6-7 ounces dark chocolate, chopped
• special equipment: a 1 1/2-inch cookie cutter