Get Ready: Preheat your oven to 375°F (190°C). Line a 12-cup muffin tin with paper liners and lightly spray them with cooking spray. Set aside.
Make the Sunny Pistachio Filling: In a small skillet, gently toast the kataifi pastry dough over low heat, stirring often, until it turns a lovely golden brown. Transfer the toasted kataifi to a medium bowl. Add the pistachio cream and tahini, then stir until everything is well combined. This is your delicious, creamy center!
Prepare the Healthy Chocolate Batter: In a large mixing bowl, whisk together the boiling water and cacao (or cocoa) powder until it's smooth and lump-free.
Next, whisk in the applesauce, maple syrup, and avocado oil until well blended.
Add the egg, baking powder, baking soda, and salt, then whisk again until the mixture is smooth.
Finally, gently fold in the flour with a spatula just until it's combined. Be careful not to overmix, as this keeps the muffins tender.
Assemble Your Muffins: Scoop about two-thirds of the chocolate batter into each prepared muffin cup. You should have about one-third of the batter remaining for later.
Take a generous scoop of your pistachio-kataifi filling and carefully place it into the center of the batter in each muffin cup, pressing it down lightly.
Cover the filling completely by dividing the remaining chocolate batter evenly among the 12 muffins, pouring it over the center. The batter should spread to cover the filling.
Bake to Perfection: Bake for about 20 minutes, or until a toothpick inserted into the chocolate part of a muffin comes out clean.
Let the muffins cool in the tin for 5 minutes, then transfer them to a wire rack to cool completely for about an hour. They get even fudgier and tastier as they cool!
Add the Sunny Chocolate Topping: In a small, microwave-safe bowl, combine the dark chocolate chips and coconut oil. Microwave in 30-second bursts, stirring in between, until the chocolate is smooth and melted.
Drizzle the melted chocolate over the cooled muffins, then immediately sprinkle with the finely chopped pistachios for a lovely crunch.
Enjoy! These muffins are best enjoyed a few hours later or even the next day when the flavors have melded and the topping has set beautifully.