Preheat oven to 350. Grease two 9x5x3 loaf pans.
Puree the beans in a food processor until smooth.
In a large bowl, blend eggs and beans well. Add butter and vanilla. Mix well.
Mix in sugar. Mix together baking soda and baking powder, salt, and cinnamon, then blend well with bean mixture. Stir in nuts. Add flour, one cup at a time, mixing well after each addition.
Divide batter into the two pans and bake for 50-60 min, until a toothpick comes out clean. Can be frozen for up to 3 months.
Optional: add 2-3 cups grated carrots or apples.