Preheat oven to 350 degrees F. Butter and flour an 8-inch loaf pan.Cream the butter and sugar with a mixer until light and fluffy. Add the egg yolks, one at a time, beating well after each addition. Gradually add the flour and blend well. Stir in the vanilla, and set aside.Add the salt to the egg whites, beat until you have stiff peaks. Delicately fold first the egg whites and then the strawberries into the batter, until blended.Pour the batter into the prepared pan and bake for 45 to 55 minutes, until a knife inserted in the center comes out clean. Leave in the pan to cool. Once cool, invert onto serving plate.To make strawberry puree, put 7-8 strawberries in a food processor and pulse until smooth.In a small bowl, cream 1 cup of the powdered sugar and the butter with a mixer until smooth. Stir in the strawberry puree. Mix in the remaining sugar gradually until the icing reaches the desired consistency. Drizzle glaze over top of cooled cake.