Wash hands with soap and water.
In a medium bowl, whisk together the eggs, brown sugar, vanilla, pumpkin pie spice, and salt. Whisk in the butter, pumpkin purée and milk.
Pour the egg mixture into an 18-inch x 13-inch baking sheet with at least ½-inch sides.
Lay the slices of bread in a single layer in the egg mixture. Then flip the bread slices so both sides have an opportunity to soak in the mixture.
Wash hands with soap and water after handling raw eggs.
Bake the French toast in the oven until the internal temperature reaches 160 °F on a digital food thermometer, about 15 to 20 minutes, turning over halfway through.
While the French toast cooks, lightly toast the pecans in a small skillet over low heat.
Sprinkle the pecans over the French toast and serve immediately.