Add the flour, salt, baking powder and cinnamon to a medium sized mixing bowl and whisk to combine. Set aside.
Add the butter, brown sugar and vanilla extract to a large mixing bowl and use an electric hand mixer to whip until pale and fluffy. About 5 minutes. Add the flour mixture and use a spatula to mix until well combined.
Split the mixture into two and wrap in plastic wrap. Place in the fridge to rest for1 hour or overnight.
Preheat your oven to 175 °C / 350 °F. Line two baking trays with baking paper. Set aside.
Dust your workbench and rolling pin with flour and roll the dough out. For this recipe you’ll need a pumpkin cookie cutter. Cut out as many cookies as you can. I got about 36 cookies.
Place them onto the baking sheets and place in the fridge to chill for 30 minutes.
Use a small knife or Stanley knife to cut out little smiles and eyes on half the cookies. Bake for 15 minutes or until golden.
Brush the cookies with melted butter and sprinkle cinnamon sugar (1/2 cup sugar mixed with 1tsp cinnamon). Allow to cool to room temperature.
Add a little bit of warmed hazelnut spread on the cookies with no face and spread out. Sandwich with the cookies that have a face. Add the remaining melted chocolate to a piping bag and fill the faces with chocolate.