Melt the white chocolate

• Place the chopped white chocolate in a bowl.
• Melt in short bursts in the microwave, stirring between each, until smooth.

Make the water ganache

• Pour the hot water over the melted chocolate.
• Whisk until completely smooth and glossy.

Color the ganache

• Add the yellow gel food coloring.
• Whisk until the color is even.

Cool to dripping consistency

• Let the ganache cool until it thickens slightly but still flows.
• Transfer to a squeeze bottle.

Drip the cake

• Pipe the ganache around the top edge of the chilled cake, letting it run down the sides.
• Fill in the top and smooth it.