Soak raw cashews in water for at least 4 hours or overnight. If short on time, boil them for 15 minutes until soft. Drain before use.

Wash and peel (optional) the Yukon Gold potatoes. Using a mandoline or sharp knife, slice them about 1/8 inch (3 mm) thick for even cooking.

In a high-speed blender, combine soaked cashews, oat milk, minced garlic, nutritional yeast, lemon juice, salt, and black pepper. Blend until completely smooth, about 1 to 2 minutes.

Pour the blended sauce into a medium saucepan. Warm over medium-low heat for about 5 minutes, stirring frequently. Do not let it boil.

Preheat the oven to 375°F (190°C). Lightly grease a 9x13 inch baking dish.

Arrange a layer of potato slices to cover the bottom, overlapping slightly. Pour about one-third of the creamy sauce over the potatoes, spreading evenly.

Repeat layering until all potatoes and sauce are used, finishing with sauce on top.

In a small bowl, mix panko breadcrumbs, chopped thyme and rosemary, garlic powder, olive oil, and a pinch of sea salt. Toss until the crumbs are evenly coated and slightly moist.

Sprinkle the herb crust evenly over the top of the scalloped potatoes. Cover loosely with foil and bake for 40 minutes.

Remove the foil and bake for an additional 15-20 minutes, or until the crust is golden and crisp and the potatoes are tender when pierced with a fork.

Let the dish cool for about 10 minutes to let the sauce thicken and settle before slicing and serving.