Preheat oven to 350 degrees F (175 degrees C). Grease and flour a 10x15 inch sheet pan.
Sift together the flour, sugar and baking soda into a large bowl. Stir together the eggs, pineapple with juice and vanilla. Make a well in the flour mixture and pour in the pineapple mixture. Mix well and spread into prepared pan.
Bake in the preheated oven for 25 to 30 minutes, or until a toothpick inserted into the center of the cake comes out clean. Allow to cool.