Preheat the oven to 180°C (approximately 350°F) convection. Line a baking sheet with parchment paper.
Beat butter with sugar and salt until creamy, then stir in the egg and peanut butter. Mix some of the flour with baking powder and cinnamon and stir into the butter mixture. Mix in a little more flour if needed for a moldable (drop cookie) consistency. Scoop with a teaspoon dipped in flour and space portions of dough slightly apart on the cookie sheet. Sprinkle with peanuts and bake cookies for about 15 minutes. Remove from the baking sheet and allow to cool before serving.