In a small, microwave safe bowl heat the chocolate chips in 30 second increments in the microwave, stirring in between, until the chips are fully melted. Set aside.
Preheat the oven to 375. Line a 12 cup muffin tin with parchment liners. In a medium sized bowl, whisk together flour, baking soda, baking powder, salt, cinnamon, ginger, and nutmeg. Set aside.
In a large bowl, whisk together the granulated sugar, brown sugar, vegetable oil, pumpkin puree, eggs, and orange juice. Pour the dry ingredients into the pumpkin mixture in two batches, whisking after each pour until the batter is fully mixed.
Fill the muffin cups 3/4 full with the pumpkin batter. Then drop a large tablespoon of the melted and cooled chocolate in the top middle of each muffin. Use a toothpick to swirl the tops.
Bake the muffins for 18-20 minutes, or until the tops start to brown and an inserted toothpick comes out clean. Let the muffins cool in the tin for 5 minutes before removing. Serve warm or room temperature.