Cocoa Surprise Cookies

1 c. softened butter
1 c sugar
1 c. packed brown sugar
2 eggs
2 t. vanilla
3 c. flour
2/3 c. cocoa
1/2 t. baking soda
2 c. semisweet chocolate chips
2 c. miniature marshmallows, frozen
In a large mixing bowl, cream butter and sugars until light and fluffy. Add eggs, one at a time, beating well after each addition. Beat in vanilla. Combine flour, cocoa and baking soda; gradually add to creamed mixture. Stir in the chocolate chips.
Roll the dough into 12" x 1 1/2" rolls. Freeze or refrigerate. Slice to bake. (375° for 7 min.) Push marshmallows into the hot baked cookies.