Preheat oven to 350ºF (175ºC). Line a 10 by 15 inches jelly roll pan with parchment and grease.
Beat eggs until frothy, then mix sugar and vanilla, and beat until thick. Add sifted flour, baking powder, and salt, oil, and soured milk.
Pour batter into pan and bake for 10 to 12 minutes.
While the cake is still hot, invert it onto a towel that has been dusted with powdered sugar, remove the parchment, and roll it up. Cool for 30 minutes.
Whip the cream with powdered sugar and vanilla to form soft peaks, then fold in the strawberries.
Unroll the cake; spread the filling, and re-roll. Refrigerate for an hour.
Finish with a sprinkle of powdered sugar, garnish, and serve.