Preparation

• ACTIVATE THE YEAST: In a small bowl, combine warm milk and a pinch of sugar, then sprinkle the yeast over the top. Let it sit for 5–10 minutes until foamy.
• MIX DRY INGREDIENTS: In a large mixing bowl, whisk together the flour, granulated sugar, and salt until evenly combined.
• COMBINE WET INGREDIENTS: Add the foamy yeast mixture, softened butter, eggs, vanilla extract, and lemon zest (if using) to the dry ingredients. Mix until a shaggy dough forms.
• KNEAD THE DOUGH: Transfer the dough to a lightly floured surface and knead by hand for 10–12 minutes, until the dough becomes smooth and elastic. Add small amounts of flour if the dough is too sticky.
• LET DOUGH RISE: Place the kneaded dough in a lightly greased bowl. Cover with a damp towel and let rise in a warm area for 1 to 1 ½ hours, or until doubled in size.
• THICKEN THE FILLING: While the dough rises, stir together raspberry preserves, cornstarch, and water in a small saucepan. Cook over medium-low heat, stirring constantly, until the mixture thickens slightly. Set aside to cool completely.
• ROLL OUT THE DOUGH: After the first rise, punch down the dough and roll it into a 10x15-inch rectangle on a floured surface.
• ADD THE FILLING: Spread the cooled raspberry mixture evenly over the dough, leaving a ½-inch border on all sides.
• FORM THE LOAF: Starting from one long edge, roll the dough into a tight log. Slice the log lengthwise down the center to reveal the layers, then twist the two halves together with the cut sides facing up.
• SECOND RISE: Gently transfer the twisted dough into a greased 9x5-inch loaf pan. Cover and let rise for another 30–40 minutes.
• PREHEAT THE OVEN: While the loaf is rising, preheat your oven to 350°F (175°C).
• BAKE THE LOAF: Brush the top of the loaf with melted butter. Bake for 35–40 minutes until golden brown and fully baked. If it browns too quickly, cover loosely with foil for the final 10 minutes.
• COOL THE LOAF: Let the baked loaf cool in the pan for 10 minutes, then transfer to a wire rack to cool completely before glazing.
• MAKE THE GLAZE (OPTIONAL): In a small bowl, whisk together powdered sugar, lemon juice, and milk until smooth. Drizzle over the cooled loaf.