Combine the sugar, baking soda, yogurt and corn syrup in lightly oiled, 4 quart saucepan. Cook over low heat, stirring constantly, until the sugar is dissolved. Wipe down sugar crystals above liquid line, using a clean pastry brush dipped in cold water. Bring to a boil.

Insert candy thermometer, cook until thermometer registers 234º. Remove from heat. Stir in butter, vanilla and pecans. Beat with wooden spoon just until mixture thickens and begins to look cloudy. Drop mixture by teaspoons onto well oiled baking sheet. Let cool completely. Store in airtight container in cool place. Makes 1 dozen.