Preheat oven to 300º F.

Place the bread cubes on a large rimmed baking sheet. Bake until lightly browned and crisp, about 15-20 minutes. Remove and cool on baking sheet.

Meanwhile, add the sausage to a hot saute pan coated with cooking spray. Brown until no longer pink, breaking into bite sized pieces. Remove with a slotted spoon and set aside. In the same pan, add the butter and onions and cook on medium-low for 25-30 minutes until the onions are very soft and caramelized.

Increase oven temperature to 375ºF.

Add the bread cubes, sausage, onions, parsley, dates and crushed red pepper flakes to a large bowl. Toss gently to combine. Add chicken stock, beaten egg, salt and pepper and toss to combine.

Generously butter a 9x3 baking dish and pour the bread mixture into the dish. Top with a sheet of parchment paper and then tightly wrap in foil. Bake for 50-60 minutes. Remove foil for the last 10 minutes of baking to crisp the top. Serve immediately.