Cinnamon Streusel Baked Apples

Name: Cinnamon Streusel Baked Apples
Prep time: 15 min
Cook time: 55 min
Total time: 1 h 10 min
Cuisine: American
Ingredients: 8 tablespoons butter, (cut into tablespoon pieces); 1 teaspoon pure vanilla extract; 1/2 cup packed light brown sugar; 1/2 cup all-purpose flour; 3/4 cup old-fashioned oats; 1/2 cup chopped pecans or walnuts; 1/2 teaspoon ground cinnamon; 1/8 teaspoon ground nutmeg; 1/8 teaspoon salt; 5 medium Honeycrisp apples ((can use Fuji, Jonagold, or Granny Smith) ); 2 tablespoons light brown sugar; 3/4 cup hot water; Vanilla ice cream (for serving, optional); Salted caramel sauce (for serving, optional)