Cut slices of challah in half and then in quarters.
Whisk together eggs, half and half, milk, maple syrup, pumpkin and pumpkin pie spice.
Assemble one layer of challah in the baking dish fitting it in like puzzle pieces
Pour 1/3 of the pumpkin mixture over the first layer of bread and then add a second layer of bread pieces on top of the first.
Pour the remaining pumpkin mixture over the bread being sure that it seeps into every crevice and covers each piece of bread up top. Move some pieces around if need be to allow pumpkin filling between each piece of bread. (It will look like you’ve got too much liquid. Don’t worry, as long as it’s not spilling out, you’re ok.)
Let the bread soak up some of the liquid for 45 minutes to 1 hour.
Preheat the oven to 350 degrees and place the baking dish on the middle rack to cook for 30 to 45 minutes or until the pumpkin is set and bread is brown.
Remove from oven and let sit for 5 minutes before cutting into squares.
Dust each serving with powdered sugar and drizzle with maple syrup. Makes about 4 to 6 servings.