Ingredients
Method
- Mix cocoa with boiling water to a smooth paste. Cool 5 minutes.
- Preheat oven to 180°C / 160°C fan / Gas 4. Line a 12-hole muffin tin with cupcake cases.
- Place flour, baking powder, bicarbonate of soda, sugar, butter, oil, eggs, milk, vanilla, and cooled cocoa paste in a large bowl. Beat 2–3 minutes until smooth. Scrape down halfway.
- Fill cases two-thirds full. Bake 18–20 minutes until risen and a skewer comes out clean. Cool in tin 5 minutes. Transfer to wire rack. Cool completely.
- Beat butter alone 4 minutes until very pale and fluffy. Add icing sugar and cocoa in 3 batches — beat well after each. Add vanilla and milk until smooth and pipeable. Beat 2 more minutes.
- Pipe or spread generously onto cooled cupcakes. Decorate. Serve at room temperature.
Notes
Bloom cocoa in boiling water — the most important step for deep chocolate flavour.
Add sunflower oil alongside butter for noticeably more moist cupcakes.
Fill cases exactly two-thirds full for a proper dome.
Beat butter alone for 4 minutes — this creates the aerated base for great buttercream.
Sift icing sugar and cocoa twice for a completely smooth buttercream.
Store in an airtight container for up to 3 days. Freeze unfrosted for up to 3 months.
