Preheat the oven to 375F
Line a jumbo muffin tin with muffin/cupcake liners (you can use a regular muffin tin, just be prepared for about 24 muffins)
In a large bowl, add flour, sugar, baking soda and salt. Mix with a fork to combine and set aside
In a medium heat-proof bowl, add cocoa powder. Pour boiling water on top and whisk until smooth. When mixture is completley smooth, add in the oil, sour cream, eggs, and vanilla. Mix again until smooth. Note that when you add the oil, the mixture will break a but but it will come back together when you add the sour cream
Once the mixture is smooth, add it to the dry ingredients in the large bowl ( flour, sugar, baking soda and salt). Mix with a nonstick spatula until smooth and add in all of the chocolate chips (reserving the chunks for topping)
Scoop batter into the prepared muffin tins until the cavities are about 3/4 full- we want big muffins!
Bake for 20-28 minutes or until a knife inserted into the center of the muffin comes out clean!
While muffins are baking, prepare the ganache
Place the chocolate in a heat proof bowl
In a different heatproof microwave-safe bowl, add the heavy cream. Microwave for 1 minute and 30 seconds or until the cream is steaming hot, just about to boil
Pour the hot cream over the chocolate and let sit for at least 2 minutes
Stir, letting the residual heat of the cream melt the chocolate until the ganache is smooth
Place ganache in a piping bag and snip a small portion of the tip of the bag (no need to use a piping tip)
Pipe a coin sized amount of the ganache on top of the cooled muffins
Let set for 10 minutes and enjoy!