Mix water and yeast together in a bowl. Let stand until yeast softens and begins to form a creamy foam, about 5 minutes.
Whisk buttermilk and oil into the yeast mixture. Stir in flour, salt, and baking soda until dough comes together.
Turn dough out onto a floured work surface; knead until smooth and elastic, about 10 minutes. Let dough rest for 15 minutes.
Whisk 3/4 cup brown sugar, 4 tablespoons melted butter, and cinnamon together in a bowl.
Roll dough out into a 12-inch long rectangle about 1/4-inch thick. Spread cinnamon mixture evenly on top. Roll up lengthwise into a log; cut into 1-inch slices using a serrated knife.
Whisk remaining 3/4 cup brown sugar, 6 tablespoons melted butter, and molasses together in a small bowl. Pour into a greased 9x13-inch baking pan. Arrange dough slices on top. Cover and let rise at room temperature for 30 minutes.
Preheat oven to 350 degrees F (175 degrees C).
Bake in the preheated oven until golden brown on top, 20 to 25 minutes.