1. Preheat oven to 300°.
2. To prepare meringues, cover a baking sheet with parchment paper. Draw 8 (4-inch) circles on paper. Turn paper over; secure with masking tape.
3. Combine egg whites and cream of tartar in a large bowl; beat with a mixer at high speed until soft peaks form. Add salt. Gradually add granulated sugar, 1 tablespoon at a time, beating until stiff peaks form. Add 2 tablespoons cocoa, 1/2 teaspoon coffee, and vanilla; beat well. Fold in 1/4 cup cacao nibs. Divide batter evenly among 8 circles on prepared baking sheet; spread to fill circles using the back of a spoon.
4. Bake at 300° for 35 minutes. Turn oven off; cool meringues in closed oven 1 hour. Carefully remove meringues from paper. Cool completely on a wire rack. (Store in an airtight container for up to a week).
5. To prepare filling, combine 3 tablespoons cocoa, 3 tablespoons boiling water, and 1/2 teaspoon coffee granules in a small bowl, stirring with a whisk until smooth. Cool. Combine powdered sugar and cream cheese in a medium bowl; beat with a mixer until smooth. Add cocoa mixture; beat well. Fold in whipped topping. Spoon 1/4 cup filling into center of each meringue; drizzle 1 teaspoon chocolate syrup over each filled meringue. Sprinkle 1/4 teaspoon cacao nibs over each serving.