How to Make It
Combine the strawberries and 1/4 cup sugar in a medium bowl. Cover and chill 1 hour; stir occasionally.
Preheat oven to 400°.
Coat a 15 x 10-inch jelly-roll pan with cooking spray; line bottom of pan with wax paper. Coat wax paper with cooking spray.
Lightly spoon flour into a dry measuring cup; level with a knife. Combine flour, baking powder, and salt, stirring with a whisk. Set aside.
Place remaining 1/2 cup sugar, egg whites, and egg yolks in a large bowl; beat with a mixer at high speed until pale and fluffy (about 5 minutes). Stir in lemon rind and vanilla. Sift half of flour mixture over egg mixture; fold in. Repeat procedure with remaining flour mixture. Spoon batter into prepared pan; spread evenly.
Bake at 400° for 10 minutes or until cake springs back when touched lightly in center. Loosen cake from sides of pan; turn out onto a dishtowel dusted with powdered sugar. Carefully peel off wax paper; let cake cool 2 minutes. Starting at narrow end, roll up cake and towel together. Place, seam side down, on a wire rack; cool completely (about 1 hour). Unroll carefully; remove towel. Spread jam over cake, leaving a 1/2-inch border. Reroll cake, and place, seam side down, on a platter. Cut into 8 slices.
Beat cream with a mixer at high speed until stiff peaks form. Serve strawberries and whipped cream with cake. Garnish with orange rind, if desired.