Warm 1 cup of milk to about 110°F (43°C). Combine warm milk with 2 teaspoons of sugar and 2 ¼ teaspoons of active dry yeast; let sit for 5-10 minutes until frothy.

In a separate bowl, whisk 4 cups of flour, ½ cup of sugar, and 1 teaspoon of salt. Mix in ¼ cup of melted butter and 1 beaten egg to form a soft dough.

Knead dough on a floured surface for 8-10 minutes until smooth and elastic. Place in a greased bowl, cover, and let rise in a warm area for 1-1.5 hours until doubled in size.

While dough rises, prepare the filling by dicing 2-3 medium apples and tossing with 2 teaspoons of cinnamon and ½ cup of brown sugar.

Preheat oven to 350°F (175°C). Roll dough into a rectangle about ¼ inch thick. Spread ¼ cup of softened butter over the surface, sprinkle with filling, and roll tightly.

Slice dough into 12 equal pieces and place in a greased baking dish, leaving space for expansion. Cover and let rise for another 30-45 minutes.

Bake in preheated oven for 25-30 minutes until golden brown and fragrant.

Let cool for 10 minutes, then drizzle warm caramel sauce over the rolls and optionally sprinkle with flaky sea salt.

Serve warm, best enjoyed with coffee or tea.