Preheat the oven to 350°F (175°C).

In a large mixing bowl, whisk together the pumpkin puree, eggs, milk, heavy cream, brown sugar, vanilla extract, pumpkin pie spice, and salt until well combined.

Cut the bread into cubes and add it to the pumpkin mixture, gently folding to coat the bread evenly.

Transfer the mixture to a greased 9x13 inch baking dish, spreading it out evenly.

In a small bowl, combine the chopped pecans, brown sugar, and cinnamon for the topping.

Sprinkle the topping evenly over the casserole.

Bake in the preheated oven for 45-50 minutes, or until the top is golden brown and the center is set.

Let it cool for a few minutes before serving.