For the Muffins:

1. Preheat oven to 425°F and grease a 6-count jumbo muffin tin or line with parchment paper liners. You can also use a 12-count muffin too (see notes).
2. In a large mixing bowl combine the flour, sugar, cocoa powder, baking soda, salt, and 1 ½ cups of the chocolate chunks.
3. In a separate mixing bowl whisk the eggs + extra yolk, sour cream, oil, milk, and vanilla extract till combined.
4. Pour the wet ingredients into the dry ingredients and mix till just combined and no dry streaks remain. Do not over mix. The batter will be thick so do not use a whisk here.
5. Fill the jumbo muffin tin all the way to the top and sprinkle the reserved chocolate chunks on top. Bake at 425 for 5 minutes. Keep the muffins in the oven but turn the temperature down to 350 and bake an additional 18-23 minutes till a toothpick comes out clean.
6. While the muffins are baking, make the ganache (see instructions below). Unless you’re using chocolate sauce – then disregard.
7. Let muffins cool in the pan for 5 minutes before removing to a wire cooling rack to cool another 10 minutes before continuing with the last step.
8. Add the chocolate ganche to a condiment squeeze bottle with a tip. Poke the tip into the top middle of 1 muffin and squeeze about a tablespoon of sauce into the muffin. Drizzle a bit on top of the muffin before continuing on with the rest of the muffins.
9. Let the muffins cool completely before storing leftovers in an airtight container at room temperature for up to 4 days.
10. If you’re using normal sized muffins, bake at 350°F for 16-20 minutes. If using tulip style parchment liners, you can fill the batter to the top. If you’re using normal cupcake liners or no liner, fill ¾ to the top.
11. If you’re buying chocolate sauce, look for the kind that comes in a squeeze bottle. If you get hot fudge, thin it out with a bit of milk.

How to Make Ganache

1. Place the chocolate chips in a small mixing bowl or glass measuring dish.
2. Pour the heavy cream into a microwaveable dish and heat until steamy.
3. Pour the steaming cream over the chocolate chips. Let it rest for 5 minutes then whisk until smooth and creamy.
4. Allow to cool for 2-3 minutes and pour into a squeeze bottle.