Prepare the Dough

1. Preheat Oven: Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper or a silicone baking mat.
2. Mix Dry Ingredients: In a medium bowl, whisk together the flour, cocoa powder, baking powder, and salt. Set aside.
3. Combine Wet Ingredients: In a large bowl, whisk the melted butter and sugar until smooth and creamy. Add the eggs, one at a time, mixing well after each addition. Stir in the vanilla extract and orange zest.
4. Combine Wet and Dry Ingredients: Gradually add the dry ingredients to the wet mixture, stirring until just combined.
5. Add Chocolate Chips: Fold in the semi-sweet chocolate chips or chunks and milk (or orange juice, if using).

Shape and Bake

1. Shape the Cookies: Drop heaping tablespoonfuls of dough onto the prepared baking sheet, spacing them about 2 inches apart.
2. Bake: Bake for 12-15 minutes, or until the cookies are set but still slightly soft in the center. They will firm up as they cool.
3. Cool: Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.