Combine sugar and corn syrup in 1 1/2 quart glass mixing bowl. Stirring well. Microwave on high for 4 minutes. Stir in pecans. Microwave on high 5 to 7 minutes, until lightly browned. Stir in butter and vanilla. Microwave 1 more minute. Stir in soda. Pour mixture onto a lightly greased baking sheet. Cool. Break into pieces and store in airtight container. Makes about 3/4 pound.