Make your Crust - Finely pulse graham crackers and cinnamon (if using) in a food processor fitted with an 'S' blade or crush crumbs in a freezer bag with a rolling pin. Then pulse or mix in the melted butter. The crumbs should resemble wet sand and should hold together easily. If the crumbs are still dry, add a bit more butter.

Transfer the crumbs into 6, 4-inch tart pans with removable bottoms. Using the bottom of a small round measuring cup, firmly press the crumbs into the bottom and up the sides of the tart pans. Transfer to a small baking tray and freeze for 15 minutes.

Make your Marshmallow Fluff  (when you are ready to serve) -  In a large heatproof bowl, add egg whites, sugar and cream of tartar and whisk until combined. 

Place bowl over a saucepan filled with 2 inches of simmering water, making sure the water is not touching the bottom of the bowl. Whisk constantly and heat until the egg white mixture reaches between 160ºC to 170ºF. With a kitchen towel, carefully remove the bowl from the pan and place on the counter. The bottom of the bowl will be steaming hot, so please proceed with caution! 

With an electric mixer, beat the egg white mixture on high speed until you get stiff peaks. Add vanilla and mix for an additional minute.

 Transfer meringue to a piping bag fitted with a tip of your choice (I used this one) or to a freezer bag with the tip cut off. Pipe the marshmallow fluff on top of the tarts.

Using a kitchen torch, carefully torch the meringue. Serve and enjoy!!