Place an extension wand on the hose of your vacuum. Turn the vacuum on and hold the opening of the wand about 1/2 inch above the cocoa powder to lift the particles from the carpet. Rolling your vacuum over the carpet can cause the particles to bind to the fibers, making the cocoa powder more difficult to remove.
Mix 1 cup of warm water and one squirt of mild laundry detergent that does not contain bleach. Dip a clean towel in the soapy water. Blot a liquefied cocoa powder stain powder from the outside to the center of the stain with the towel.
Spray a carpet stain lifting product that does not contain bleach on a clean towel. Blot the liquefied cocoa powder with the stain lifter, moving from the outside in. Dab a clean, dry towel on the treated area to absorb the cocoa powder onto the towel.