Begin by cutting your sturdy, country-style or sourdough bread into bite-sized cubes, approximately 1-inch pieces. Place the bread cubes in a greased baking dish.

In a large mixing bowl, whisk together your chosen plant-based milk, flaxseed meal, maple syrup, vanilla extract, cinnamon, and nutmeg until smooth and creamy.

Gently fold in the fresh or frozen blueberries into your custard mixture with a spatula.

Evenly pour the custard mixture over the prepared bread cubes, ensuring all pieces are soaked adequately. Allow to sit for at least 30 minutes at room temperature, or refrigerate overnight.

Preheat your oven to 350°F (175°C) for baking.

Mix your chosen toppings like pecans or oats until combined, then sprinkle evenly over the casserole.

Bake for 45-50 minutes until golden brown and firm in the center.

Allow to cool for a few minutes on a wire rack before serving.