Stir brown sugar, chopped pecans and pumpkin pie spice into melted butter. Spread into a greased 9×13-inch pan.
Line the pan with 1 1/2-inch thick slices of French bread cut at a diagonal.
Beat the eggs, half-n-half, pumpkin puree until smooth. Slowly pour the mixture over the French bread slices in the pan. Cover the pan and place in the fridge for at least one hour (or overnight).
Bake uncovered at 375 degrees for 35-40 minutes.
Remove from the oven and flip the pan over onto a rimmed baking sheet so that the caramel pecan bottom is now the caramel pecan top!