Preheat oven to 350 degrees F. Brush a large baking dish (10 x 14 inches) with 2 tablespoons of butter.
In a large bowl whisk together eggs, brown sugar, cream and milk. Stir in vanilla, spices, sweet potato purée, pecans and bread, blending thoroughly. Stir in remaining 2 tablespoons butter and pour into baking dish. Bake until just firm, 1 hour. Cool pudding in dish on a baking rack until just warm, then cut into squares to serve.
Yield: 10 to 12 servings