Beat brown sugar and butter together in a bowl using an electric mixer until smooth and creamy; add egg and vanilla extract and beat until smooth. Add flour, baking soda, and salt; beat until dough is blended. Fold cocoa nibs and cherries it batter. Drop batter by the spoonful onto a baking sheet.
Bake in the preheated oven until cookies are beginning to brown around the edges, 10 to 12 minutes. Cool cookies on baking sheet for 2 minutes before transferring to a wire rack to cool completely.
