Sift dry ingredients:

Sift the flour, baking powder, and salt together in a bowl; set aside.

Prepare orange components:

Halve one orange and squeeze out the juice; set aside. Remove the peel from the second orange and cut it into chunks.

Whisk wet mixture:

In a separate medium bowl, whisk together the egg, sugar, milk, orange chunks, reserved orange juice, and melted butter until thoroughly blended.

Combine wet and dry:

Add the liquid mixture to the dry ingredients, stirring minimally until a moist batter just comes together.

Fold in chocolate chips:

Carefully fold the chocolate chips into the batter.

Fill muffin cups and bake:

Divide the batter among silicone or paper-lined muffin cups. Bake at 380°F (195°C) for approximately 25 minutes.