Take a cue from the French and bake meringues in a rainbow of colors. Crispy on the outside and chewy on the inside, they're utterly irresistible. Start with Martha's chocolate version, then try the raspberry and orange variations.
Preheat oven to 300 degrees.
In the bowl of an electric mixer fitted with the whisk attachment, beat together egg whites and salt on high speed until glossy peaks form. With mixer running, add sugar in three additions, beating until meringue is stiff and glossy. Sprinkle in cornstarch, vinegar, and vanilla; gently fold to combine. Sift cocoa over meringue; gently fold so that streaks of cocoa remain.
Using a 1/2-cup ice cream scoop, drop 6 balls of meringue onto a parchment-lined baking sheet, spacing about 3 inches apart. Bake until puffed and slightly cracked, 30 minutes. Turn off oven and let meringues stand at least 2 hours or up to overnight.
RaspberryFold in 1/4 cup freeze-dried raspberries, finely ground in a food processor, and pink gel food coloring instead of cocoa powder.OrangeFold in 1/4 cup finely chopped candied orange peel and orange gel food coloring instead of cocoa powder.