Preheat oven to 425 degrees. Poke a few holes in sweet potatoes and place on bottom rack. Bake for about 45 minutes or until easily pieced with a dinner fork.
While the potatoes roast, prep the bread pudding ingredients: tear or cut bread into one-inch pieces and place into a large bowl. Set aside.
Remove sweet potatoes and reset oven to 350 degrees. Place in freezer for a few minutes to make them easier to handle then peel off the skin (they should come away easily) and place sweet potatoes in a bowl. Mash to your desired consistency using a wooden kitchen spoon.
In a large bowl, whisk together eggs until uniform. Mix in sugar, pumpkin puree, heavy cream, half and half, melted butter, vanilla extract, cinnamon, nutmeg, and sea salt then stir in the cooled sweet potatoes. This custard mixture will have some chunks of sweet potato, which is OK.
Pour custard mixture into bowl of torn bread pieces and use a spoon or rubber spatula to mix and spread the mixture until all pieces of bread are evenly coated. Transfer to a non-stick oblong pan and smooth top of mixture with spoon or spatula until it is relatively flat and even. Place pan in oven to bake for about an hour and thirty minutes.
While the bread pudding bakes, melt the butter for the praline sauce in a small saucepan over medium-low heat.
Add brown sugar and cream and stir until mixture is uniform. Bring to a boil then reduce heat to low and simmer for five to 10 minutes in order to allow sauce to thicken. Remove from heat and stir in pecans.
When ready to serve, you can either spoon the sauce all over the bread pudding before cutting or ladle it on the individual portions. Both ways work fine but the first is easiest with a large crowd.