Preheat the oven to 350°F (175°C) and line a 9x13-inch baking pan with parchment paper.

In a medium bowl, whisk together the all-purpose flour, cream of tartar, baking soda, ground cinnamon, ground nutmeg, ground cloves, and salt.

In a large bowl, mix the melted butter, granulated sugar, and brown sugar until smooth. Add the pumpkin puree, egg, egg yolk, and vanilla, stirring until incorporated.

Gradually fold the dry ingredients into the wet mixture until just combined.

Pour the batter into the prepared pan, spreading it evenly.

In a small bowl, mix granulated sugar and ground cinnamon, then sprinkle evenly over the batter.

Bake for 30-35 minutes until edges are golden and a toothpick comes out with a few moist crumbs.

Let cool in the pan on a wire rack before slicing into squares.