Karidopita (Greek Nut Cake)

Ingredients

• 6 eggs
• 1 cup white sugar
• 1 cup brown sugar
• 1 cup peanut oil
• 1 1/3 cups buttermilk , with the yellow flakes
• 2 1/2 cups flour
• 1 teaspoon baking soda
• 1 teaspoon baking powder
• 1/2 teaspoon salt
• 2 teaspoons cinnamon
• 1/2 cup spiced rum
• 2 cups finely chopped walnuts
• 2 1/2 cups white sugar
• 1 1/4 cups water
• 1 1/2 teaspoons cinnamon
• 2 medium sized lemon slices , diced and smashes , saving all of the juices
• 2 medium sized orange slices , diced and smashed , saving all of the juices
• 1/2 cup finely chopped walnuts