Preheat your oven to 400°F (200°C). Lightly grease a 9x13 inch baking dish.

In a large mixing bowl, combine the thawed and squeezed hash browns with 2 tbsp olive oil, 1/2 tsp garlic powder, 1/2 tsp onion powder, 1/2 tsp sea salt, and 1/4 tsp black pepper. Mix well to ensure the hash browns are evenly coated.

Press the seasoned hash browns firmly into the bottom of the prepared baking dish in an even layer. Bake for 20 minutes, or until lightly golden and somewhat crispy. Remove from oven and reduce oven temperature to 375°F (190°C).

While the hash browns are baking, heat 1 tbsp olive oil in a large skillet over medium heat.

Crumble the pressed extra-firm tofu into the hot skillet. Cook for 5-7 minutes, stirring occasionally, until some moisture has evaporated and the tofu starts to brown slightly.

Add the nutritional yeast, black salt (kala namak), turmeric powder, garlic powder, and black pepper to the tofu. Stir well to combine and cook for another 2-3 minutes, ensuring the turmeric evenly coats the tofu for color. Set aside.

In the same skillet (no need to clean it), heat 1 tbsp olive oil over medium heat. Add the diced yellow onion and red bell pepper. Cook for 5-7 minutes until softened.

Add the sliced mushrooms and cook for another 3-5 minutes, until they release their moisture and start to brown.

Stir in the chopped fresh spinach and cook until wilted, about 1-2 minutes. Remove from heat.

In a small saucepan, melt 2 tbsp vegan butter over medium heat.

Whisk in 2 tbsp all-purpose flour and cook for 1 minute, stirring constantly, to create a roux.

Gradually whisk in 1.5 cups unsweetened plain plant milk until smooth and no lumps remain. Continue to whisk as the sauce thickens, about 3-5 minutes.

Remove from heat and stir in 1/2 cup shredded vegan cheddar cheese, 2 tbsp nutritional yeast, 1/2 tsp garlic powder, 1/4 tsp smoked paprika, and an optional pinch of cayenne pepper. Stir until the cheese is melted and the sauce is smooth. Season with salt and pepper to taste.

Spread the sautéed vegetables evenly over the partially baked hash brown crust in the baking dish.

Crumble the cooked tofu scramble over the vegetable layer.

Pour the vegan cheese sauce evenly over the top of the tofu and vegetables.

Bake in the preheated oven at 375°F (190°C) for 35-40 minutes, or until the casserole is bubbly around the edges and the top is lightly golden brown.

Let the casserole rest for 10-15 minutes before slicing and serving. This helps it set and makes for cleaner slices.