For the muffins:

1. Preheat the oven to 425 degrees.
2. In a large bowl, add the salt, pumpkin spice, ginger, ground cinnamon, baking soda, and flour and whisk until the flour mixture is combined.
3. In a small bowl, add the milk, coconut oil, pumpkin puree, granulated sugar, brown sugar, and eggs and stir until completely combined and smooth.
4. Add the wet ingredients to the large bowl with the dry ingredients and stir until the muffin batter is combined and smooth. Make sure to scrape the bottom of the bowl to combine all of the flour and there are no lumps.
5. Place the paper liners in the muffin pan and using a large spoon, fill each of the muffin cups to the top of the pan. 
6. Place the muffins in the center of the oven and bake for 5 minutes at 425 degrees.
7. Reduce the heat to 350 degrees and bake for another 20 to 22 minutes or until a cake tester comes out clean when inserted into the middle of a muffin. 
8. As the muffins come out of the oven, press chocolate chunks into the top of each muffin. The chocolate chunks will melt and stick to the muffin top.
9. Use a sturdy straw to make a long narrow hole in the center of each muffin and be careful not to go all the way through the bottom. Alternatively, you could use a paring knife to cut a slit in the center of each muffin.

For the molten chocolate:

1. In a small saucepan, melt the butter, and then add the heavy cream, cocoa powder, sugar, and salt to the melted butter. Over medium heat, stir until combined. Cook for 1 to 2 minutes until it bubbles and the chocolate is smooth and creamy.
2. Remove from heat and let it cool to room temperature.
3. Pour the chocolate sauce into a pastry bag or a small ziplock freezer bag with a tiny corner cut off of the bottom of the bag. 
4. Carefully fill each hole in the muffins with molten chocolate. You will likely need to do this in several steps as the chocolate settles into each muffin.