Lightly oil bottom and sides of a 15- x10- x1-inch jellyroll pan with vegetable oil; line with wax paper and lightly oil and flour wax paper. Set aside.

Beat egg yolks at high speed of an electric mixer until foamy. Gradually add 1/4 cup sugar; beating until mixture is think and lemon colored (about 5 minutes). Stir in vegetable oil and vanilla; set aside.

Beat egg whites (at room temperature) until foamy; gradually add remaining 1/2 cup sugar, beating until egg whites are stiff but not dry. Fold whites into yolks. Combine flour, baking powder, and salt; gradually fold into egg mixture. Spread batter evenly into prepared pan. Bake at 350" for 8 to 10 minutes.

Sift powdered sugar in a 15 x 10 inch rectangle on a cloth towel. When cake is done, immediately loosen from sides of pan, and turn out onto sugared towel. Carefully peel off wax paper. Starting at narrow end, roll up cake and towel together; let cake cool completely on a wire rack, seam side down.

Unroll cake. Spread cake with half of White Chocolate Cream Filling and carefully reroll cake, without towel. Place cake on a serving plate, seam side down; spread remaining filing on all sides. Garnish with white chocolate curls.