Preheat oven to 250F and line a baking sheet with parchment paper.
In the (clean and grease free) bowl of a stand mixer with the whisk attachment, beat the egg whites and the cream of tartar until they start to get foamy.
Then, with the mixer running on medium-high speed, slowly add the sugar, about a spoonful at a time, allowing each spoonful to get mixed in for 30 seconds or so before adding more.
Continue whipping on high speed until the meringue is glossy and stiff peaks form (about 5-7 minutes)
Scoop the meringue into a piping bag fitted with a large, plain piping tip. I used a Wilton 1A tip.
Pipe "stems" by slowly lifting up the piping tip and releasing so that you have a short cylinder, pointy tips are ok.
Pipe "mushroom caps" by piping small circles and gently flattening down any tips that form with your finger.
Bake for 1 hour and 30 minutes. The meringues should release from the paper easily and be firm to the touch. Allow to cool before assembling.
To assemble the mushrooms, melt the chocolate in a double boiler or the microwave using short bursts. Stir until smooth.
With a small knife, gently carve a small hole into the underside of the meringue mushroom caps, being careful not to poke all the way through the caps.
Place a little bit of melted chocolate in the hole on the underside of the mushroom caps, and gently spread a little more chocolate over the whole flat underside of the mushroom caps, if desired. Insert the stems into the little holes to create your mushrooms.
Set the finished cookies upside-down until the chocolate has hardened.
Finally, lightly dust the mushroom caps with a little bit of cocoa powder.
Serve on a plate with tea or after dinner coffee, or carefully place in a basket for gift giving. Be careful, the cookies are fragile.
Nutritional information is provided as a courtesy and is an estimate only. This information comes from online calculators. Although The View from Great Island attempts to provide accurate nutritional information, these figures are only estimates.
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