Preheat oven to 350 degrees F (175 degrees C). Grease a 11x13-inch baking pan.
Place raisins in a pot, cover with water, and simmer until soft, 20 to 30 minutes.
Drain raisins and place in a blender. Add pureed pumpkin, eggs, and oil; blend everything until pureed.
Combine oat flour, spelt flour, almond meal, coconut flour, amaranth flour, brown rice flour, baking soda, salt, cinnamon, allspice, nutmeg, and cloves in a bowl. Pour in pumpkin mixture and stir until well combined. Fold in pecans. Pour batter into the prepared pan.
Bake in the preheated oven until a toothpick inserted into the center comes out clean, about 30 minutes.