Start Squash Tacos: In a food processor, combine breadcrumbs, paprika, onion powder, garlic powder, cinnamon, salt, and black pepper (see note 3). Pulse until breadcrumbs are half their original size. Transfer to a plate.
Coat squash: Pour milk into a medium bowl. Dip a piece of squash in milk, then into breadcrumbs (use your clean hand to press breadcrumbs onto squash). Place the squash onto a parchment lined baking sheet. Repeat to coat all pieces. Bake until golden brown, 30 to 40 minutes, flipping half way.
Make Crema: Meanwhile, rinse and drain soaked cashews. To a blender, add cashews, avocado, jalapeno, lime juice, grapeseed oil, 2 tablespoons of the water, and salt. Blend until smooth, adding additional water to thin, if needed. Scoop the sauce out of the blender and set aside.
Assemble: Wrap a stack of tortillas in foil. When the squash is almost done, add the tortillas to the oven and bake until warm, about 10 minutes. Serve with crema and toppings of your choice.
Notes
Soaking cashews: The cashews should be soaked to the point that they feel soft when squeezed between your fingers. You can quick-soak cashews by pouring boiling water over them and soaking for at least 30 minutes; or use room-temperature water and soak overnight.
Food processor alternative: If you don't have a food processor, you can pulse the breadcrumbs in the blender once or twice (be careful not to over process though, because you still want some texture). Or, place the breadcrumbs in a resealable freezer bag, then run a rolling pin over top.