Grandma's Irish Soda Bread

Bahan-bahan (1 porsi)

• 1 and 3/4 cups (420ml) buttermilk*
• 1 large egg (optional, see note)
• 4 and 1/4 cups (531g) all-purpose flour (spooned & leveled), plus more for your hands and counter
• 3 Tablespoons (38g) granulated sugar
• 1 teaspoon baking soda
• 1 teaspoon salt
• 5 Tablespoons (71g) unsalted butter, cold and cubed*
• optional: 1 cup (150g) raisins