Preheat oven to 350 degrees F.
Put syrup in a shallow bowl. Put a thin slice from bottom of each pear so that the pears will stand upright. Dip and roll each pear in maple syrup to coat completely, reserving remaining syrup. Transfer pears as coated to a 9 by 2-inch square baking pan, standing them upright.
Sprinkle pears with 2 tablespoons sugar, holding by stems and tilting to coat sides. Stir lemon juice, 2 tablespoons Calvados, and butter into reserved syrup and pour around pears in pan.
Bake pears, uncovered, in middle of oven until undersides are tender when pierced with a knife, about 30 minutes.
Beat cream with remaining tablespoon sugar and remaining tablespoon Calvados with an electric mixer until it holds soft peaks.
Divide pears and syrup among plates and serve warm, with whipped cream on the side.