Add a bit of cream to the pan after you’ve sautéed the sausage to deglaze so you don’t lose all the deliciousness in the brown bits.Preheat oven to 200 degrees. Place brioche cubes in a single layer on a sheet tray and bake until firm and dry, about 30 minutes.While bread is drying, brown sausage over medium heat until cooked through. Drain on a paper towel-lined plate.Preheat oven to 350 degrees. Prepare a 9-cup casserole dish by lightly greasing with butter. Build bread pudding in dish by adding in single layers: brioche, sausage, kale, squash.Whisk together eggs, yolks, and cream. Season to taste and pour over the assembled ingredients (custard mixture will not cover rest of ingredients; press down lightly to help bread absorb the liquid and let rest 20 minutes).Bake for about 50 minutes, or until top of casserole is brown and begins to puff (when eggs are set).