Chocolate Brownie Croquembouche

Line 1-3/4- x 3/4-inch (4.5 x 2 cm) mini-muffin cups with paper liners. Place 3 white chocolate chips in each cup; set aside.

In bowl over saucepan of hot (not boiling) water, melt unsweetened chocolate with butter; let cool for 10 minutes.

In separate bowl, beat eggs with granulated sugar until pale and thickened, about 5 minutes. Beat in vanilla and chocolate mixture. In small bowl, whisk flour with baking powder; stir into chocolate mixture. Spoon into cups, filling three-quarters full.

Bake in centre of 350°F (180°C) oven until just firm to the touch, 12 to 15 minutes. Let cool in pan on rack for 10 minutes; transfer to rack. Let cool completely. (Make-ahead: Store in airtight container for up to 1 day or freeze for up to 1 month.)

Chocolate Icing: In bowl, beat butter with icing sugar until fluffy; beat in bittersweet chocolate until blended. Spread over brownies.

Garnish: Decorate with gold flakes and sprinkles as desired.

On 9-inch (23 cm) tall foam cone with 4-inch (10 cm) wide base and holding toothpick at sharp angle, press two-thirds of toothpick into cone near base. Press 1 side of brownie onto toothpick to secure. Repeat with remaining brownies to cover cone, leaving scant 1/2 inch (1 cm) between each row. (Make-ahead: Wrap with plastic wrap and store for up to 1 day.)