In Lagos, Nigeria, where the hum of the city mingles with the aroma of freshly baked bread, Chef Juliet Aigbe, known affectionally as “Chef Juls,” slides a grain-free wedding cake into a large commercial oven. Her award-winning bakery, Cakeflair, is more than just a place where wholesome baked goods are crafted; it’s the site of a movement that draws from the soil of her...