Based on you description helical mixer is recommended for blending these type of materials similar to what is used in paste blending frequently.

But I concern about your small amount of material or 10 mL of volume to be mixed. May be it is necessary to rebuild a tiny blender.

Please refer to following link to get more about helical mixers:

http://www.biodiesel-machine.com/sesame-paste-mixer.html

Once, you can try with tissue homogenizer..

once you can try with ultra homogenizer

You can also use geometric mixing to mix powder in viscous liquid using glass slab and spatula.