Preheat oven to 375 F.
In pot over medium heat, melt butter. Add flour and cook 4 minutes, stirring occasionally. Reduce heat to low then slowly add milk gradually, ensuring it is incorporated before adding more. Turn heat to medium-high and cook until thickened, stirring continuously. Remove from heat and set aside.
In bowl, add drained potatoes, sauce, bacon, cinnamon, nutmeg, ginger and cloves. Season with salt and pepper, to taste; mix well.
In greased 8-by-11-inch baking dish, line potatoes on sides in desired pattern. Stuff extra bacon between potatoes from remains left in bowl. Pour extra sauce over potatoes.
Bake 60 minutes.
In small pot over medium-high heat, add brown sugar and water. Cook to melt sugar and allow to bubble, about 5 minutes. Add pecans; stir 2 minutes. Lay on parchment-lined baking sheet and allow to cool. Once cool, chop into pieces.
Remove potatoes from oven and sprinkle pecans over top.