How to Make It
Preheat the oven to 325°. Butter a 9-by-5-inch loaf pan. In a medium bowl, whisk together all but 2 tablespoons of the all-purpose flour with the buckwheat flour, baking soda, baking powder, salt, ground ginger, cloves and cinnamon. In a small bowl, toss the raisins with the remaining 2 tablespoons of all-purpose flour.
In a medium bowl, mix the pumpkin with the carrots, grated ginger and sour cream. In a small bowl, whisk the eggs with the oil and vanilla.
In the bowl of an electric stand mixer fitted with the paddle, cream the butter with the sugar at medium-high speed until light in color, about 2 minutes. Scrape down the side of the bowl and beat in the egg mixture at low speed. Increase the speed to medium high and beat until fluffy, about 2 minutes. Scrape down the bowl again. Add the pumpkin mixture and beat at medium speed until fully incorporated. Add the dry ingredients all at once and mix at low speed just until incorporated. With a rubber spatula, fold in the raisins.
Scrape the batter into the prepared pan. Bake for about 1 hour and 50 minutes, or until a skewer inserted in the center comes out clean. Let the bread cool in the pan for 20 minutes, then turn it out onto a rack. Turn the loaf right side up and let cool completely. Serve at room temperature.