1 large apple, (Granny Smith or Golden Delicious), peeled, cored and roughly chopped

1 1/4 cups buttermilk, mixed with 2 teaspoons vanilla extract

Powdered sugar, for dusting

1. Preheat the oven to 350 F. Butter and flour a 10-cup bundt pan or a 9- by 13-inch baking dish and set aside.

2. Make the streusel: In a medium bowl, combine the brown sugar, ginger, cinnamon, flour and butter, and cut together with two knives, your fingers or a pastry blender until the mixture resembles large bread crumbs. Mix in the walnuts and set aside in the refrigerator until ready to use.

3. Prepare the cake: Sift together the flour, ginger, cinnamon, nutmeg, baking powder, baking soda and salt into a medium bowl. Stir in the crystallized ginger and set aside.

4. In a large mixing bowl, beat the butter with an electric mixer until light and fluffy. Gradually add the sugars, continuing to beat until very light. Add the eggs one at a time, beating well before adding the next. (Don't overbeat or the cake will be tough.) Gently stir in the chopped apples. With the mixer on low speed, alternately beat in the flour mixture and the buttermilk, beating until the batter is just mixed.

5. Spoon half of the batter into the pan and sprinkle with 1/3 of the streusel. Spoon on the remaining batter and smooth out to an even layer. Sprinkle the remaining streusel evenly on top. Pat it down gently.

6. Bake until the top of the cake is firm and the streusel is crisp and golden brown, (a skewer inserted into the center of the cake should come out clean), about 40 to 45 minutes. Cool for 15 minutes in the pan on a wire rack. If using a bundt pan, invert the cake onto a wire rack and then invert it back onto a serving platter so that the streusel side is on top. Dust with powdered sugar and serve warm.

Advance Preparation: Can be prepared up to 1 day ahead, covered and kept at room temperature.

(Diane Rossen Worthington is an authority on new American cooking. She is the author of 18 cookbooks, including "Seriously Simple Parties," and a James Beard Award-winning radio show host. You can contact her at www.seriouslysimple.com.)