Preheat oven to 300 degrees

In a medium bowl, add both suggar, cinnamon, and salt and mix together, then set aside.

In a large bowl, whisk the egg white, vanilla, and water, then add the pecans and gently toss until the pecans are well coated. Add the sugar and cinnamon mixture and toss until pecans are covered.

Spread the pecans out in a single layer on prepared baking sheet. Bake for about 30-45 minutes, stirring every 15 minutes. Watch to make sure they are browning too quickly.

Remove from the oven and let the pecans cool on the baking sheet.

In a large bowl, whisk together the flour, baking powder, cornstarch, cream of tartar, and salt.

In a stand mixer, cream the softened butter and sugar until light and fluffy.

Beat in the egg, vanilla, and pumpkin puree until fully combined.

Gradually add the flour mixture until well blended.

If the dough seems too wet, add a bit more flour, one tablespoon at a time.

Cover the dough and refrigerate for 30 minutes to 1 hour (the longer the better)

Preheat the oven to 350°F

Remove the dough from the refrigerator and on a lightly floured surface roll it out into a circular shape

Transfer cookie dough to a well greased pizza pan and press it down to cover the entire surface of the pan. If you don't have a pizza pan, they you can use a mixing bowl to trace a circular pattern out of the dough and then bake on a cookie sheet

Bake for 10-12 minutes, removing when it still feel undercooked. Don't let it brown around the edges.

Transfer to a wire rack to cool completely.

In a small pan over low heat, add marshmallow and maple syrup and stir until fully melted

Immediately pour the marshmallow onto the cookie and spread evenly across the cookie crust

Sprinkle the candied pecans evenly over top