I love this baking idea! I've seen berries and fruit slices baked inside cakes, but never entire pears. Deanna Segrave-Daly made this cake with Meyer lemons, a variety of that plant that is increasingly popular with chefs in America. She made her batter with Greek yogurt, a whole vanilla bean and whole wheat pastry flour.
She poached 3 Bosc pears in sugar water. Maybe she did this to keep the pears moist, which I expect would be a problem when baking pears inside a cake. Segrave-Daly sliced the bottoms off the pears so that they could stand upright in the baking pan, then poured the batter in.