Pumpkin French Toast Casserole

Name: Pumpkin French Toast Casserole
Ingredients: 5 tablespoons unsalted butter, melted, plus more for buttering the pan; One and one-half 15-ounce cans pumpkin puree; One 14-ounce can sweetened condensed milk; 1 cup milk; 1 teaspoon ground cinnamon; 1 teaspoon vanilla extract; 4 large eggs; 1 loaf brioche bread, sliced; Two 8-ounce packages cream cheese, at room temperature; 1 cup powdered sugar; 1 cup chopped pecans; 1/2 cup packed brown sugar; Pinch of salt; Maple syrup, for drizzling