In a medium bowl, whisk together the flour, cornstarch, cream of tartar, cinnamon, salt, baking soda, ginger, nutmeg, and cloves to combine.
In a large bowl, use an electric mixer to beat the butter, coconut oil, and sugars on medium-high speed until light and fluffy, about 2 to 3 minutes. Add the pumpkin puree and beat to combine. Add the egg yolk and vanilla and beat until combined. Slowly beat in the flour mixture. Dough will be soft and slightly sticky.
Cover with plastic wrap and chill in the fridge for at least 1 hour or until firm enough to scoop. You can also refrigerate for up to 24 hours, just let sit at room temperature until malleable enough to scoop.
Combine the 1/4 cup of sugar with the cinnamon in a shallow dish. Using a spring-loaded scoop, divide the dough into 3-tablespoon sized balls, then roll in sugar to coat evenly. Place the dough balls on the prepared baking sheets, spacing 2 inches apart, and flatten with the bottom of a measuring cup or glass. Sprinkle lightly with additional cinnamon sugar, if desired.
Bake for 10 to 12 minutes, or until the cookies are set and beginning to brown at the edges. Let the cookies cool for 5 minutes before removing to a wire rack to cool completely. Store in an airtight container at room temperature for up to 3 days.