2 c. unsifted all-purpose flour
2 tsp. baking powder
1/4 tsp. baking soda
1/2 tsp. salt
1 tsp. ground cinnamon
1/2 tsp. freshly grated nutmeg
1/4 tsp. ground allspice
1/4 tsp. ground ginger
1/2 c. chopped walnuts
4 tbsp. (1/2 stick) unsalted butter, melted and cooled
1/3 c. firmly packed light brown sugar
1/3 c. granulated sugar
2 extra lg. eggs, at room temperature
2 tbsp. milk, at room temperature
2 tbsp. light cream, at room temperature
1 tsp. pure vanilla extract
2 tsp. finely grated orange rind
1 c. steamed and pureed sweet potatoes, at room temperature

CINNAMON-WALNUT TOPPING:

2 tbsp. cold unsalted butter, cut in sm. cubes
4 tbsp. chopped walnuts
3 tbsp. granulated sugar
1 tsp. ground cinnamon

Lightly butter and flour a 10 x 3 3/4 x 3 inch loaf pan; set aside. Preheat the oven to 350 degrees.

Sift together the flour, baking powder, baking soda, salt, cinnamon, nutmeg, allspice and ginger onto a large sheet of waxed paper. Place the walnuts in a small bowl and toss with 1 teaspoon of the sifted mixture.

Stir together the melted butter, brown sugar and granulated sugar in a large mixing bowl, using a wooden spoon or flat paddle. Beat in the eggs, one at a time, blending well after each one. Beat in the milk, cream, vanilla, orange rind and pureed sweet potatoes. Add the sifted flour mixture and stir. Fold in the floured walnuts. Spoon the batter into the prepared pan.

For the topping, put the butter cubes, walnuts, sugar and cinnamon in a small mixing bowl. Crumble the mixture together with your fingertips until the butter is broken down into small bits. Sprinkle the topping evenly over the top of the cake.

Bake the cake on a rack placed in the lower third of the preheated oven for about 45 minutes, or until a wooden pick inserted into the center of the cake comes out clean and dry.

Let cool in the pan on a wire rack for 5 minutes. Invert onto a second cooling rack, then invert again to cool. Makes one 10 x 3 3/4 x 3 inch loaf cake.