In a large bowl, cream butter and sugars until light and fluffy. Add eggs, one at a time, beating well after each addition. Beat in vanilla. Combine the flour, cocoa and baking soda; gradually add to the creamed mixture and mix well. Stir in chocolate chips.
Roll into 1-1/2-in. balls. Press two to three frozen marshmallows into each; reshape balls.
Place 2 in. apart on ungreased baking sheets. Bake at 400° for 8-10 minutes or until set. Cool for 5 minutes before removing to wire racks to cool completely.