2/3 cup all-purpose flour
3 tablespoons unsalted butter, cut into small pieces, at room temperature
1 tablespoon granulated sugar
1 tablespoon confectioners' sugar
Pinch kosher salt
2 large eggs
1/4 cup heavy cream
2 tablespoons packed dark brown sugar
1 teaspoon pure vanilla extract
1/4 teaspoon ground cinnamon
1/4 teaspoon ground allspice
3/4 cup sweet potato puree
2 tablespoons unsalted butter, melted
1/2 cup mini marshmallows or 2 big dollops lightly sweetened whipped cream, for serving