Preheat the oven to 350 degrees F. Grease 2 (9-inch) cake pans with shortening and set aside.
Cream together the shortening and the sugar. Combine the flour, baking powder, and salt. Slowly alternate adding the egg yolks and milk with the dry ingredients and mix until well combined. Add the vanilla and mix well.
Pour into the prepared pans, about 550 grams of batter for each cake. Bake for 18 to 20 minutes. Remove from oven and cool on a rack.