Grease bottom and sides of a 15x10x1-inch jelly roll pan then line bottom with waxed paper; grease the paper.
Into a bowl, sift together the sifted cake flour, baking powder, and salt. Set aside. In a small bowl beat eggs at high speed of electric mixer. Gradually beat in sugar; add vanilla and beat until fluffy, thick, and lemon-colored, about 5 minutes. Gradually fold in sifted flour mixture.
Pour batter into prepared 15x10x1-inch jelly roll pan. Bake at 400° for 10 to 12 minutes, until cake bounces back when lightly touched in center.
Dissolve gelatin in hot water; add cold water. Blend thoroughly and chill until slightly thickened. Fold in the chopped strawberries, salt, and 2 tablespoons of confectioners' sugar. Refrigerate until the filling is thicker, about jam/jelly consistency; stir mixture occasionally.
Invert cake onto a dish cloth which has been sprinkled generously with confectioners' sugar. Carefully peel off waxed paper and trim off crisp edges. While still hot roll cake with cloth from narrow end. Cool rolled up cake on a rack. When cool, unroll. Remove the cloth and spread thickened filling over the cake. Roll up and place on serving plate, seam side down. Spread cake with whipped topping or cream, sprinkle with toasted sliced almonds and garnish with reserved strawberries.
Keep strawberry cake roll refrigerated until serving time. Serves 10.
Note:To toast almonds, spread out in a single layer on a baking sheet. Toast in a 350° oven, stirring occasionally, for 10 to 15 minutes. Or, toast in an ungreased skillet over medium heat, stirring, until golden brown and aromatic.