Apple Cider Coffee Cake

Name: Apple Cider Coffee Cake
Prep time: 30 min
Cook time: 1 h 10 min
Total time: 1 h 40 min
Cuisine: American
Ingredients: 32 fluid ounces apple cider; 170 grams unsalted butter (room temperature); 50 grams granulated white sugar; 53 grams dark brown sugar; 1 large egg (room temperature); 1 tablespoon vanilla extract; 1/2 teaspoon diamond-crystal kosher salt (plus more for seasoning) (use 1/4 teaspoon if using any other brand of salt); 1 1/2 teaspoons baking powder; 1/2 teaspoon baking soda; 1 1/2 teaspoons ground cinnamon; 60 grams full-fat sour cream (1/4 cup | chilled or at room temperature); 188 grams all-purpose flour; 62 grams all-purpose flour; 106 grams dark brown sugar; 1/2 teaspoon ground cinnamon; 1/4 teaspoon diamond-crystal kosher salt (use 1/8 teaspoon if using any other brand of salt); 57 grams unsalted butter (melted and then cooled slightly); 5 ounces peeled and sliced apples (from about 1 apple | sliced into 1-inch pieces with 1/8-inch thickness ); 1 teaspoon all-purpose flour