Mix 1/2 cup of the yogurt, 2 tablespoons of the sugar and 1 teaspoon of the vanilla in a small bowl. Refrigerate until ready to use.
Place remaining 1/2 cup yogurt, remaining 1/4 cup sugar, orange juice concentrate, milk, remaining 1 teaspoon vanilla and orange extract in blender container; cover. Blend on high speed until smooth. Pour mixture into 10 popsicle molds, leaving a small space at the top for the yogurt layer.
Freeze 1 hour. Top each popsicle mold with a spoonful of the chilled yogurt mixture. Insert a popsicle stick into each mold. Freeze 8 hours longer or until frozen.