Preheat oven to 250°.
Combine cream of tartar, salt, and egg whites in a large bowl; beat with a mixer at medium speed until soft peaks form. Add sugar, 1 tablespoon at a time, beating at high speed until stiff peaks form. Add extracts; beat just until blended (do not overbeat). Gently fold in coconut. Drop by rounded tablespoons, 2 inches apart, onto 2 baking sheets covered with parchment paper. Bake at 250° for 1 hour until very lightly browned and almost crisp, switching baking sheets and rotating front to back halfway through baking time. Remove from oven. Cool for 25 minutes (meringues will crisp as they cool). Sprinkle evenly with 1 tablespoon cocoa.