Preheat oven to 325 degrees. Place bread on a large baking sheet in a single layer, and bake until dry and crisp, about 4 minutes total. Turn slices over at 2 minutes for even baking. Remove from oven and allow bread to cool. When bread has cooled, butter slices on one side using 3 tablespoons of butter. Melt remaining 2 tablespoons of butter in nonstick skillet over medium heat. Saute shallots until fragrant and translucent. Add spinach, 1/2 tsp. salt and 1/4 tsp. pepper, and saute another 2 minutes. Transfer contents to a bowl and set aside. Add wine to skillet. Increase heat to medium-high, and deglaze pan until wine is reduced to 1/4 cup. Take off heat and set aside.