Preheat oven to 350F. Spray a 9x5-inch loaf pan with cooking spray or grease and flour it, then set aside.

Peel the sweet potatoes, chop into 1-inch chunks. Microwave covered with 3 tablespoons water for about 15-17 minutes until fork-tender. Mash and let cool.

In a bowl, whisk together eggs, oil, buttermilk, and vanilla. Add the cooled mashed sweet potatoes and mix well.

In a large bowl, combine flour, sugars, baking soda, cinnamon, ginger, nutmeg, allspice, cloves, and salt. Whisk to promote even mixing.

Pour wet mixture into dry ingredients, stir until just combined. Avoid over-mixing.

Pour batter into prepared loaf pan and smooth the top. Bake for 60-70 minutes until golden and a toothpick comes out clean.

Cool in pan for 10 minutes, then transfer to a wire rack to cool completely.