In a large bowl, whisk with electric mixer egg whites until soft peaks do, gradually add 1/3 cup sugar and continue beating until peaks are firm but no dry, set aside. In another bowl combine flour, 1/2 cup sugar, salt, add vanilla, milk, oil and egg yolks, and mix it at medium speed for 3 minutes, scraping the sides and bottom frequently. Join the two mixtures well, pour into pan and bake 25-30 minutes, or until a tooth pick inserted in center comes out clean. Cool completely on wire rack. When the cake is cool, with a sharp knife, mark a circle of one centimeter deep and with a spoon remove the mass of the cake. Make a syrup with 3 tbsp sugar and 1 tbsp water and let boil until is light consistency and hot pour over the edge cake. Make a vanilla pudding as directed on package, and pour in the circle you did in the cake.
For another version: You can use chocolate or your favorite flavor pudding.
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