In bowl of an electric mixer fitted with paddle attachment, beat cream cheese, sugar and cinnamon on medium speed until light and fluffy, approximately 2-3 minutes; set aside.
In a large glass measuring cup or another bowl, whisk together milk, pumpkin puree, eggs, pumpkin pie spice and vanilla.
Lightly coat an 9x13 baking dish with nonstick spray. Place a layer of bread cubes evenly into the baking dish. Pour half of the pumpkin puree mixture evenly over the top. Spread cream cheese filling in an even layer. Top with remaining bread cubes and pumpkin puree mixture to completely cover the filling.
Cover and place in the refrigerator for at least 2 hours or overnight.
Preheat oven to 350 degrees F.
Combine flour, sugar and cinnamon in a small bowl
Add cold butter and toss to coat, using your fingers to work the butter into the dry ingredients until it resembles coarse crumbs.
Sprinkle the crumb topping evenly over the bread cubes.
Place into oven and bake for 35-45 minutes, or until golden brown.
Serve immediately, sprinkled with pecans and confectioners' sugar, if desired.