01 -
Preheat oven to 175°C. Line a standard cupcake tin with 10 paper liners.
02 -
In a large bowl or stand mixer, combine softened butter, granulated sugar, and light brown sugar. Beat until pale and fluffy.
03 -
Mix in the egg and vanilla extract. Add salt, baking soda, and dark cocoa powder. Scrape down the bowl for even mixing.
04 -
Blend in the sour cream thoroughly, then add milk and coffee syrup. Mix at low speed to avoid splashing.
05 -
Add flour and mix until just combined, ensuring no streaks of flour remain. Do not overmix.
06 -
Divide batter evenly among the prepared liners, filling them approximately two-thirds full. Bake for 18–20 minutes at 175°C, or until a toothpick inserted into the centre comes out clean or with a few moist crumbs.
07 -
Allow cupcakes to cool in the pan for several minutes before transferring to a wire rack. Cool entirely before frosting.
08 -
In a clean large bowl or stand mixer, beat cream cheese and softened butter until light and fluffy. Add vanilla extract and coffee syrup. Scrape down the bowl.
09 -
Mix in light brown sugar, then add powdered sugar one cup at a time until desired creamy and pipeable consistency is achieved.
10 -
Transfer frosting to a piping bag fitted with a large closed star tip or alternate tip as desired. Pipe generous swirls of frosting atop cooled cupcakes. Optionally, garnish with chocolate sprinkles.
11 -
Serve immediately or store cupcakes at room temperature or in the refrigerator for up to several days. For a softer texture, allow chilled cupcakes to come to room temperature before enjoying.