1. In a small saucepan, melt butter over low-medium heat. Turn off the heat.

2. Add all the chocolate pieces and stir with  spatula to melt the chocolate. 

3. In a small bowl, whisk together flour, baking powder, and salt; set aside.

4. In a large bowl, whisk eggs, sugar, vanilla extract, orange zest, until it is homogenous.

5. Pour chocolate-butter mixture into egg mixture. Stir to combine. 

6. Slowly incorporate dry ingredients into chocolate and egg mixture, stirring after each addition.  

7. Cover the bowl with plastic wrap.  Chill dough in refrigerator for at least 1 hour.

8. Preheat oven to 350 degrees F.  Line a baking sheet with parchment paper.

9. Place 1/2 cup of icing sugar into a small dish. Using a small ice cream scoop, scoop dough and roll into balls. Roll dough into icing sugar then place cookies 1 inch apart on a cookie sheet.

10. Bake for 12 min.