Mocha Chip Meringues
Adapted from Martha Stewart
3/4 cup sugar
1 tbs cornstarch or potato starch
3 large egg whites, room temperature
1/4 tsp salt
1 tsp instant espresso powder
3 tbs unsweetened cocoa powder
1/2 cup dark chocolate pieces
Preheat oven to 300ºF, with racks in upper and lower thirds. Line two large baking sheets with parchment paper; set aside.
Whisk together sugar and cornstarch in a small bowl.
In a large bowl, beat egg whites and salt on medium speed until frothy. Add sugar mixture 1 tablespoon at a time while beating continuously. Continue beating until stiff, glossy peaks form, around 6 to 8 minutes total. Scrape down the bowl if needed. Add in espresso powder and cocoa; beat until well blended. Fold in chocolate pieces.
Fill pastry bag with batter. Pipe batter onto prepared baking sheets in even circles, about 1 tablespoon each. Leave about 1 inch between each meringue. Bake until crisp, about 40 minutes, rotating sheets halfway through. Cool completely on sheets, about 20 minutes.
Meringues can be stored in an airtight container at room temperature for up to one week.