Begin by cutting your stale loaf of bread into 1-inch cubes or thick slices. Place the bread in a large mixing bowl or directly into a greased casserole dish.

In a separate bowl, whisk together dairy-free milk, packed brown sugar, cornstarch, ground cinnamon, vanilla extract, and black salt. Allow the mixture to sit for about 5 minutes to thicken slightly.

Pour the custard mixture evenly over the prepared bread, ensuring each piece is well-soaked. Cover with plastic wrap and let it soak for at least 30 minutes or refrigerate overnight.

If using a pecan crumble topping, mix all-purpose flour, chopped pecans, vegan butter, sugar, and ground cinnamon in a bowl until it resembles coarse crumbs.

Preheat your oven to 350°F (180°C). Remove the plastic wrap from your casserole and sprinkle the pecan crumble topping over the soaked bread. Bake for 30-40 minutes until golden brown on top.

Allow to cool for a few minutes, dust with powdered sugar, and serve warm with optional toppings such as maple syrup or fresh fruit.