Chocolate Cupcakes with Chocolate Icing

Line 12 muffin cups with paper liners or grease. In small bowl, stir milk with lemon juice. Set aside.

In large bowl, beat butter with sugar until fluffy; beat in egg and vanilla. In separate bowl, sift together flour, cocoa, baking powder, baking soda and salt ; with wooden spoon, stir into butter mixture alternately with milk mixture, making 2 additions of dry ingredients and 1 of milk.

Spoon into prepared muffin cups, filling about two-thirds full. Bake in centre of 375°F (190°C) oven until cake tester inserted in centre comes out clean, about 15 minutes. Transfer to rack; let cool completely. (Make-ahead: Store in airtight container for up to 24 hours or wrap individually in plastic wrap and freeze for up to 2 weeks.)

Chocolate Icing: In heatproof bowl over saucepan of hot (not boiling) water, melt chocolate; let cool.

In large bowl, beat butter until fluffy. Beat in half of the sugar, then the cream, then remaining sugar. Beat in melted chocolate and vanilla. Spread over cupcakes. Decorate with sprinkles. (Make-ahead: Store in single layer in airtight container for up to 24 hours.)