Cut pears in half and core with a spoon, also removing the woody spine leading up to the stem. (You can cook pears in halves or cut each half in to slices and arrange them in a fan pattern). Toss in lemon juice and set aside.
Grease a skillet (or several smaller skillets), an 11x7-inch baking dish, or several wider/shallow ramekins. Set aside.
In a large bowl, whisk together the flour and sugar. In another bowl, whisk together the milk, eggs, maple syrup and vanilla. Whisk egg milk mixture in to flour mixture until combined.
Arrange pears in prepared baking dishes (I like to put a cored half pear in the centre, if space permits, with sliced pears around the outside OR cut cored half pears in to slices and arrange in fan patterns). Pour batter over-top, filling your shallow baking dish to about 2/3 full or to cover a half pear by about 2/Dot the top with diced butter. Place baking dish on to a baking sheet (just in case!).
Bake in preheated 375 oven until pears are tender and custard is puffed, set and golden, about 45 minutes.
Sprinkle with some icing sugar and place under oven broiler until bubbly and glazed, about 1 minute. Let cool on a rack for 15 minutes before serving. Lovely served slightly warmed with a dollop of whipped or ice cream.