Preheat the oven to 350°F (175°C) and lightly coat an 8x8 inch baking dish with non-stick spray.
Place the bread cubes into the prepared baking dish in an even layer.
In a large mixing bowl, whisk together the chocolate protein powder, unsweetened almond milk, liquid egg whites, cocoa powder, sweetener, vanilla extract, and salt until no lumps remain.
Slowly pour the protein liquid mixture over the bread cubes, using a spatula to press the bread down to ensure every piece is fully submerged and saturated.
Allow the dish to sit at room temperature for 15 minutes to facilitate maximum absorption of the custard into the bread.
Evenly distribute the sugar-free chocolate chips over the top of the pudding.
Bake for 35 to 40 minutes, or until the custard is set and the center no longer jiggles when shaken.
Remove from the oven and allow to rest for at least 10 minutes before serving to allow the internal structure to firm up.