3 egg whites, at room temperature
1/4 teaspoon cream of tartar
3/4 cup fine white sugar
1/4 teaspoon salt
2 teaspoons instant coffee or espresso powder
1 tablespoon cocoa powder
Heat oven to 300F. Beat egg whites until foamy. Add cream of tartar and beat until soft, bubbly peaks form. The peaks will still flop over; they’re like bubble bath still. Turn the mixers to high and add the sugar a couple tablespoons at a time. As they get glossy, beat in the flavorings. The texture should be glossy and tacky, with peaks that stand straight up.
Pipe onto parchment-covered sheets. The parchment is essential; these will stick like crazy. Bake for about two hours then turn off the oven and let them cool. They should be completely dry with no chewiness inside.