In a small bowl, combine warm milk, 1 tsp sugar, and yeast. Let sit 5–10 minutes until foamy.

In a large bowl or stand mixer, whisk together flour, sugar, and salt.

Add eggs and yeast mixture to flour mixture, mix until sticky dough forms.

Gradually knead in softened butter until dough is smooth and elastic.

Place dough in greased bowl, cover, and let rise 1–2 hours until doubled.

Prepare raspberry filling: mix preserves with lemon juice and cornstarch, cook lightly if needed, then cool.

Punch down dough, roll into 12 x 16 inch rectangle, spread filling leaving 1-inch border.

Roll dough into a log, seal edges, place in greased loaf pan, seam side down.

Cover and let rise 45–60 minutes until puffy.

Preheat oven to 350°F (175°C). Brush loaf with egg wash.

Bake 35–40 minutes until golden brown. Tent with foil if browning too fast.

Cool on wire rack. Optional: drizzle with glaze of powdered sugar, milk, and vanilla.

Slice with serrated knife and serve warm or at room temperature.