Step 1

Make the cupcakes: Preheat the oven to 350 degrees F. Line a 6-cup muffin pan with paper liners. Whisk the cocoa powder with 1/3 cup hot water in a bowl. Whisk in the chocolate syrup until smooth; let cool slightly. In a large bowl, whisk the flour, granulated sugar, baking soda, baking powder and salt.

Step 2

Whisk the vegetable oil, egg, milk and vanilla into the cocoa mixture until smooth, then fold into the flour mixture until just combined. Divide among the muffin cups. Bake until a toothpick comes out clean, 18 to 20 minutes. Let cool 10 minutes in the pan, then remove to a rack to cool completely.

Step 3

Make the frosting: Put the chocolate in a microwave-safe bowl; microwave on 70 percent power in 30-second intervals, stirring, until melted. Let cool slightly. Beat the butter, vanilla and confectioners' sugar with a mixer on medium-high speed until fluffy. Add 3 tablespoons milk; beat until smooth, 3 minutes. Remove half of the frosting to a separate bowl; add the cocoa powder, melted chocolate and a pinch of salt and beat until fluffy, 2 minutes. Mix the remaining 1 tablespoon milk and the malted milk powder in a cup, then add to the plain frosting; add a pinch of salt and beat until fluffy, about 2 minutes. If the frosting is too soft, cover and chill until it is firm enough to pipe.

Step 4

Frost the cupcakes (see below) and top with pretzel rods.

Step 5

How to swirl the frosting:

Step 6

Put the 2 frostings in separate pastry bags (or zip-top bags). Snip off the tips. Position side by side in another pastry bag fitted with a large star tip.

Step 7

Pipe the frosting onto the cupcakes in a spiral motion to create a swirl.