Mushrooms made from meringue are the traditional edible decoration for a Yule log cake, and their cute quotient is high—they never fail to charm young and old alike. Saying they're edible is like calling a chocolate truffle edible; if you love crisp meringue, you'll adore the crunchy, airy contrast the mushrooms provide for our creamy Tiramisu Yule Log cake. Classically they're made from a white meringue, but we couldn't resist coloring ours with a little added cocoa to make the mushrooms look like cremini or baby bellas.
•To melt chocolate, finely chop it then put it in a microwave-safe bowl and microwave at 50 percent power for short intervals (about 30 seconds), stirring after each interval, until smooth. Or, melt finely chopped chocolate in a dry metal bowl set over a saucepan of barely simmering water, stirring occasionally, until smooth.
•Meringue mushrooms can be made 1 day ahead and kept between sheets of wax paper in airtight cookie tins.