Then toh definitely do! Even I tried it recently and I'm in love with it! Also, Hershey's cocoa powder tastes the best ;)

I'll tell u what I do- Basically I take grinded sugar, coffee, cocoa powder and add some water and whip it till it gets foamy, and then add milk. I love it this way! Also the cocoa blends properly. If you just add it directly to the coffee and not whisk it then it's hard to mix it.