Preheat oven to 350 degrees. Grease a 9x5x3-inch loaf pan. Combine the flour, sugar, baking powder, and salt in a large mixing bowl. Stir with a fork to mix all dry ingredients well. Cut the butter into small pieces and drop into the flour mixture. Using your fingers or a pastry cutter, rub or cut the cold butter into the flour until mixture resembles coarse bread crumbs. Beat the eggs well in a small bowl, add the jam or preserves and milk; whisk until the mixture is blended smooth. Stir the egg mixture into the flour mixture and stir only until no flour streaks show--the mixture will be lumpy. Spoon into the loaf pan and bake for about 1 hour 15 minutes, or until a straw inserted into the center comes out clean. Allow loaf to remain in the pan for 15 to 20 minutes before turning it out onto a rack. Meanwhile, make the glaze by combining the butter, sugar, and jam in a pan. Stir and bring to a simmer; continue stirring until dissolved and blended. Strain and then spoon the glaze over the loaf after it has cooled on the rack.
Source: The Breakfast Book, Marion Cunningham