With the rack in the upper third position, preheat the oven to 200 °C (400 °F). Line two baking sheets with parchment paper.
In a bowl, combine the flour, baking soda and salt. Set aside.
In another bowl, cream the butter and peanut butter with the brown sugar with an electric mixer. Add the egg and beat until incorporated. At low speed or with a wooden spoon, stir in the dry ingredients and candy pieces.
With floured hands, shape 30 ml (2 tablespoons) balls of dough and place on the baking sheets. With your fingers or a fork, flatten slightly.
Bake for 9 to 10 minutes or until lightly browned. Cool completely on the baking sheet.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.