Meringue Mushrooms

NOTE: If the caps and stems become soggy during storage, crisp them in a 200-degree oven for 30 minutes before assembling the mushrooms. Make sure to save some extra chocolate buttercream for attaching caps and stems.

INSTRUCTIONS:

1. Adjust oven racks to center and low positions and preheat oven to 200 degrees. Line two jelly roll pans with parchment paper.

2. Combine ¹/₄ cup water and sugar in small, heavy saucepan. Cover and bring to boil over medium-high heat. Boil, swirling pan once or twice, until sugar has dissolved, 1 to 2 minutes. If necessary, wash down any sugar crystals on side of pan with damp pastry brush. Cook, uncovered, until temperature on thermometer registers 238 degrees, about 10 minutes.

3. While syrup is cooking, place egg whites in large bowl of standing mixer fitted with wire whisk attachment. Beat at medium-low speed until frothy, about 1 minute. Add salt and cream of tartar and beat, gradually increasing speed to high, to soft peaks, about 1 minute.

4. With mixer at medium speed, slowly pour hot syrup into egg whites, avoiding wire whisk. Increase speed to medium-high speed and continue to beat until meringue cools to room temperature and becomes very thick and shiny, 5 to 10 minutes. Add vanilla.

5. Fit pastry bag with ¹/₄-inch pastry tip and fill with meringue. Pipe caps and stems onto paper-lined pans (see figures 38 and 39).

6. Bake meringue for 2 hours, turn off oven, and let rest in oven until very dry and crisp, about 30 minutes longer. Cool mushroom caps and stems on pans. (Store in airtight container for up to 1 week.) To assemble mushrooms, use buttercream to "glue" caps and stems together (see figures 40 and 41).