Chocolate Butter Cupcakes

Chocolate Butter Cupcakes (adapted from Rose Levy Beranbaum's Rose's Heavenly Cakes)
(makes 16 cupcakes)

Ingredients:
42g unsweetened alkalized cocoa powder (I use Valrhona)
118g boiling water
2 large eggs, room temperature
3 tbsp water
1 1/2 tsp pure vanilla extract
166g cake flour
200g caster sugar
2 tsp baking powder
1/8 tsp baking soda
1/2 tsp salt
170g unsalted butter, room temperature

Method:
1. Preheat oven to 175°C and line a muffin pan with 16 paper liners
2. Whisk cocoa powder and boiling water until smooth. Cover with plastic wrap to prevent evaporation and cool to room temperature
3. In a small bowl, whisk the eggs, 3 tbsp water and vanilla until lightly combined
4. In a bowl of stand fitted with a flat beater (I use a hand mixer), mix flour, sugar, baking powder, baking soda and salt on low speed for 30 seconds
5. Add butter and chocolate mixture and mix on low speed until the dry ingredients are moistened
6. Raise speed to medium and beat for 1 1/2 mins. Scrape down the sides of the bowl
7. Starting on medium-low speed, gradually add the egg mixture in 2 parts, beating on medium speed for 30 secs after each addition to incorporate the ingredients and strengthen the structure
8. Use a no. 30 ice cream scoop or spoon to place the batter (50g) onto the prepared cupcake liners, abt 3/4 full
9. Bake for 20 to 25 mins or until a wire cake tester inserted in the centers comes out clean and cupcakes spring back when pressed lightly in the centers
10. Let cupcakes cool in pans on a wire rack for 10mins. Remove from pans and set them on a wire rack to cool completely