Using a box grater, grate the vegetables. Combine the zucchini and cauliflower into one bowl, put the purple potatoes in another bowl. Add 1 T salt to each mixture, let it sit for 5 mins and using a towel, squeeze out any excess liquid. To each bowl, add ½ c flour, ½ red onion, 1 t baking powder, and two eggs. Mix together until well combined. Set aside. In a food processor, blend together spinach, apples, and season with salt and pepper. Blend until an applesauce-like consistency forms, set aside. In a skillet, over a medium-high heat, add the cooking oil. Dollop the mixtures (2 T at a time) onto the pan, youâll be able to fit about 4 latkes on the pan at a given time. Fry in the pan for 5 mins per side until nice and crispy. Set aside on a paper towel covered plate to remove any excess oil. Garnish with sour cream and green apple sauce.