In 4-quart Dutch oven, mix 1 1/2 cups sugar, the water, ginger and lemon juice. Heat to boiling over medium-high heat. Boil 2 minutes, stirring occasionally, until sugar is melted. Stir in almond extract. Add pear halves; cover and return to boiling. Reduce heat; simmer covered 8 to 10 minutes or until pears are tender when pierced with tip of knife. Remove pears from liquid, using slotted spoon, to bowl; cover and refrigerate until serving.
Boil remaining pear liquid over high heat 8 to 10 minutes, stirring occasionally, until slightly thickened and syrupy. Cool 30 to 40 minutes or until warm. Refrigerate 2 hours or until serving.
Meanwhile, in 10-inch nonstick skillet, cook almonds over medium heat 4 to 6 minutes, stirring constantly, until just beginning to brown. Sprinkle 4 teaspoons sugar over almonds. Continue cooking and stirring 2 to 3 minutes longer or until sugar is melted and almonds are coated. Spread almond mixture on sheet of foil sprayed with cooking spray. Cool 2 to 3 minutes; break apart.
Place pear halves, cut sides up, in individual dessert bowls. (If desired, cut thin slice from rounded side of each pear half so that it won't roll around in bowl.)
Place small scoop (about 2 tablespoons) frozen yogurt in center of each pear half. Spoon syrup over top. Sprinkle with almonds.