Preheat oven to 350 degrees F (175 degrees C). Spread olive oil on a large baking sheet.
Mix water and soy flour together in a bowl to form a thick, pancake-like batter.
Stir bread crumbs, herbes de Provence, garlic powder, salt, pepper, and cayenne pepper together on a shallow plate.
Dip zucchini spears into the batter. Roll in bread crumb mixture to coat. Place spears cut-side down on the prepared baking sheet, all facing the same direction.
Bake in the preheated oven until lightly golden, about 10 minutes. Turn to other cut side and bake for 10 minutes. Turn spears so they are skin-side down; continue baking until browned, about 5 minutes more.
Transfer zucchini spears to a platter. Serve with vegan mayonnaise and ketchup.