Pumpkin Spice French Toast Casserole

Name: Pumpkin Spice French Toast Casserole
Ingredients: 1 tablespoon unsalted butter, at room temperature; One 1-pound loaf Italian-style bread, sliced 1/2-inch-thick; 4 large eggs; 1/3 cup sugar; 2 teaspoons pumpkin pie spice; 1 teaspoon pure vanilla extract; 1/2 teaspoon kosher salt; 2 cups whole milk; 1 cup heavy cream; 1 cup pumpkin pie puree (not pure pumpkin puree); 3/4 cup packed light brown sugar; 1/4 cup all-purpose flour; 1/4 teaspoon kosher salt; 1 stick unsalted butter (8 tablespoons), cut into cubes; 1 cup chopped pecans