Activate Yeast: Combine 1 ½ cups of warm milk, 2 ¼ teaspoons of active dry yeast, and ½ teaspoon of white sugar in a bowl and let sit for about 5 minutes until frothy.

Prepare Dough: Mix 3 ½ cups of all-purpose flour, 1 teaspoon of salt, and ¼ cup of white sugar in a stand mixer, then add the frothy yeast mixture and knead for 2 minutes.

Knead and Rise: Incorporate 4 tablespoons of softened butter and knead for 5-7 minutes until smooth, then let it rise in a warm spot for 30-60 minutes.

Roll Dough: Roll the dough into a rectangle measuring approximately 10 by 20 inches.

Add Filling: Brush with 4 tablespoons of melted butter, sprinkle with ½ cup of brown sugar, ½ cup of white sugar, and 2 teaspoons of ground cinnamon, then roll tightly.

Make Topping: Combine 4 tablespoons of melted butter, 1 cup of brown sugar, ½ teaspoon of vanilla extract, ¼ teaspoon of ground cinnamon, ¼ cup of heavy cream, and a pinch of salt; heat until boiling.

Final Rise: Cut the rolled dough into 8-12 pieces, arrange in the prepared pan over the pecan layer, and let rise for 30 minutes.

Bake: Preheat oven to 350°F (175°C) and bake for 25-30 minutes until golden brown.

Cool and Serve: Let the buns rest for 15 minutes, then invert onto a serving plate.