In heavy, large saucepan, stir sugar, syrup, 2 cups water over medium heat until sugar is dissolved.
Continue cooking, without stirring to 238° on candy thermometer, or until a little dropped in cold water forms a soft ball - will take about 15 minutes.
Add nuts; cook, stirring occasionally, until syrup turns golden - to 300° on candy thermometer, about 20 minutes.
Add butter and sota; stir until blended.
Pour into prepared pans, forming a large square of brittle in each pan.