Preheat the oven to 350C. Line a baking tray with parchment paper. Place softened butter and egg into a large bowl and beat with an electric mixer until smooth. Add cookie dough mix and mix until a dough forms. 1 ½ “ balls of dough. Place onto the baking sheet with 2 inches between each cookie. Bake for 15 minutes until golden. Allow to cool completely before cutting in half.