Spray the crockpot with cooking spray, and turn heat to high.
Place the croissants on a cutting board, or mat, and cut into 1 inch cubes. Cut the jumbo pumpkin muffins into 1 inch cubes, and add both to the Crockpot, tossing with your hands to blend. Place lid on the crockpot.
In a large measuring bowl, or bowl with a pouring spout, place the 8 ounces of cream cheese, and place the bowl in the microwave.
Microwave for about 1 minute, stirring half way through, to soften the cream cheese, making it easy to stir. Stir the cream cheese with a large spoon until it's smooth and creamy.
Stir in the sugar (1 cup) and keep stirring until the sugar is completely blended. Add the can of pumpkin, and stir to blend.
Add the Sweetened Condensed Milk, Egg, Cinnamon, Pumpkin pie spice, and Vanilla, and stir until blended and smooth.
Pour mixture over cubed Croissants and pumpkin muffins, and stir to mix.
Cook on high for about 1 to 1/2 hours, and then turn the heat to low, and finish cooking, for about 2 - 3 hours, or until a knife inserted in the middle comes out clean.