Step 1: Preheat your oven to 350°F (175°C). Lightly spray a 9x13-inch baking dish with cooking spray. Tear the day-old bread into 1-inch pieces and spread them evenly in the prepared dish.
Step 2: In a large bowl, whisk together the heavy cream, half and half, pumpkin puree, granulated sugar, melted unsalted butter, large eggs, vanilla extract, and pumpkin pie spice until well combined and smooth.
Step 3: Carefully pour the pumpkin mixture evenly over the torn bread pieces in the baking dish, ensuring that all pieces are thoroughly coated and begin to soak up the custard.
Step 4: Let the bread soak for about 10-15 minutes at room temperature. This allows the bread to absorb the liquid, ensuring a rich and moist pudding.
Step 5: Place the baking dish in the preheated oven and bake for approximately 1 hour, or until the top is golden brown and the pudding is set. A knife inserted into the center should come out mostly clean.
Step 6: While the bread pudding bakes, prepare the praline sauce. In a medium saucepan, melt 1/2 cup unsalted butter over medium heat.
Step 7: Stir in 1/4 cup heavy cream and 1/2 cup packed light brown sugar. Bring the mixture to a gentle boil, stirring constantly.
Step 8: Reduce the heat to low and simmer for 5 minutes, stirring occasionally. Add the 1 cup of chopped toasted pecans and 1/2 teaspoon of pumpkin pie spice to the sauce, cooking for an additional 2 minutes. Remove from heat.
Step 9: Once the bread pudding is done baking, remove it from the oven and immediately pour the warm praline sauce evenly over the top. Serve warm and enjoy!