Blueberry Shortbread Bars

Ingredients

• 1/2 cup cold unsalted butter, cut into small cubes
• 1 1/2 cups sifted all-purpose flour
• 1/2 cup white sugar
• 1/2 teaspoon salt
• 1/4 teaspoon baking powder
• 1/4 teaspoon Chinese five-spice powder
• 1 egg yolk
• 1/2 teaspoon ice water, or more if needed
• 3/4 cup fresh blueberries