In a mixer, beat butter and sugars till well combined.
Add the eggs and vanilla to blend.
Slowly add in the flour, soda, salt and cocoa.
Once dough has formed, scoop a large tablespoon of dough-stuff a rolo in the center and surround with the dough so it's hidden.
Roll in sugar and place on parchment lined cookie sheet.
Bake approx. 10 minutes.
Cool, take a picture and eat! Mmm