In a saucepan, mix together sugar and cocoa. Add milk and corn syrup and stir. Bring to boil, lower heat and simmer for 8 to 10 minutes, stirring occasionally. When a drop forms a firm ball in cold water, remove from heat.
Stir in butter and vanilla. Beat well with a large spoon until mixture loses its gloss. Stir in candied fruit and nuts.
Pour into buttered 8 or 9 inch square pan. When set, cut in squares.