For the cupcakes:
1 cup granulated white sugar
¾ cup plus 2 tbsp all-purpose flour
¼ cup plus 2 tbsp unsweetened cocoa powder, sifted
¾ tsp baking powder
¾ tsp baking soda
½ tsp salt
1 egg, room temperature
½ cup sour cream, room temperature
¼ cup sunflower oil
1 tbsp pure vanilla extract
½ cup / 120mL boiling water
For the frosting:
6 tbsp unsalted butter, melted
½ cup unsweetened cocoa powder
¼ cup milk
2 ¼ cups confectioners’ sugar
¾ tsp pure vanilla extract
1 tsp golden syrup / light corn syrup
Preheat the oven to 350F. Line standard muffin tins with paper liners.
In a large mixing bowl, whisk together the granulated sugar, all-purpose flour, cocoa powder, baking powder, baking soda and salt. Add the egg, sour cream, oil and vanilla. Mix with a silicon spatula just until smooth and combined. Pour in the boiling water, and slowly mix. The batter will be liquid-y, this is normal.
Divide the batter evenly among the lined cups.
Bake for 15-19 minutes, rotating the pans halfway through, until a cake tester or a wooden toothpick inserted into the center of each cupcake comes out clean.
Transfer cupcakes in pans to wire racks for about 10 minutes until the tins are cool to the touch. Once the tins are cool, remove the cupcakes from the pans, and transfer to the wire racks. Let the cupcakes cool completely before frosting.
In a large bowl (or in a stand mixer), combine the melted butter and cocoa powder powder until smooth. Now, alternately mix in the milk and powdered sugar, beating (on medium speed) to spreading consistency. Add another tablespoon or so of milk, if necessary. Mix in vanilla and golden syrup / light corn syrup.
Note: The frosting recipe provided can easily frost all 16 cupcakes. However, if you’d prefer to have tall “hats” of chocolate frosting on each of your cupcakes, as pictured in this post, 1 ½-ing the recipe will be necessary.
To frost the cupcakes, I use a small off-set spatula (you can use a butter knife without a serrated edge, if you don’t have one) at an angle to spread the frosting smoothly around the cake. Make sure to frost to the very edges (doing this is not only an excuse to have more frosting on your cupcakes — yum! — but it also helps keep the cupcakes moist). Then, I use a cake spatula to create the indent in the center. You can shave some dark chocolate on top using a vegetable peeler (or you can use a microplane or one of those manual cheese graters that they use at Italian restaurants to grate Parmesan), and you’re done.