– 10 tablespoons (141g) unsalted butter – 2 cups (240g) all-purpose flour – 1 teaspoon baking soda – 1/2 teaspoon baking powder – 1 teaspoon ground cinnamon – 1/2 teaspoon salt – 1/2 teaspoon ground nutmeg – 1/4 teaspoon ground ginger – 1/4 teaspoon ground cardamom – 1/4 teaspoon ground allspice – 1/2 cup (100g) granulated sugar – 1/2 cup (100g) firmly packed light brown sugar – 2 large egg – 3/4 cup (170g) sour cream – 1 teaspoon vanilla extract – 12 pecan halves, for garnish – 1 to 2 teaspoons turbinado sugar or other coarse sugar, for garnish