1 tablespoon baking powder

4 medium eggs

1 1/2 cups sugar

Juice of 1 medium orange, about 1/2 cup

Zest of 1 medium orange, finely chopped

1/2 cup olive oil

Powdered sugar, for garnish

Whipped cream, optional

1. Preheat the oven to 350 F. Spray a 9-inch diameter spring-form pan with olive oil spray on the bottom and sides. Process the walnuts in a food processor fitted with the metal blade, until they are finely ground, almost like bread crumbs. Combine the ground walnuts, flour and baking powder in a mixing bowl, and set aside.

2. Using an electric mixer on medium, beat the eggs until they are frothy. Gradually add the sugar and beat the mixture until it is light, thick and pale yellow, about 4 minutes. Gradually add the walnut flour mixture; then add the orange juice, orange zest and olive oil, mixing just to combine.

3. Transfer the batter into the spring-form pan; place on a rimmed baking sheet. Bake for 50 to 60 minutes or until a skewer comes out clean. Cool cake completely in pan on a rack. Release the sides of the pan. Place the cake on a serving platter and sprinkle powdered sugar in a decorative pattern on top. Slice and serve with whipped cream, if desired.

(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.)