Homemade Orange Milano Cookies

Ingredients

• 1/2 cup (60 g) white whole-wheat flour or all-purpose flour
• 1/2 cup (60 g) white spelt flour or all-purpose flour
• 1/2 cup (60 g) ground millet or cake flour
• 1 tsp baking powder
• 1/2 tsp kosher salt
• 8 tbsps (1/2 cup) unsalted butter, room temperature
• 1/2 cup (110 g) powdered sugar, sifted
• 2 large egg whites (about 66 g)
• 2 tsps vanilla extract
• 1/4 cup (2 oz.) orange juice (or use milk if making mint milanos)
• 1/4 cup (2 3/8 oz.) heavy cream
• 6 ounces semi-sweet or milk chocolate, chopped
• 1 orange, zest of (or use 2 drops of peppermint oil if making mint milanos)