Preheat oven to 375 degrees. Cream butter, 1 cup sugar, and brown sugar in a bowl. Add eggs and vanilla then mix well. In a separate bowl, combine flour, cocoa, and baking soda. Add flour mixture to the creamed mixture and stir until combined. Unwrap Rolo candies and shape one tablespoon of dough around each candy. Roll in remaining 1/4 cup of sugar. Place on a parchment lined baking sheet. Bake for 7 - 9 minutes or until top is slightly cracked. Remove from baking sheet and allow to cool. Makes about 4 1/2 dozen.