Use unflavored cannabis extract. The more refined the better.
So... and I might just be high here, but so... does unflavored mean it tastes more like cannabis, or it tasteless?
Because some people just don't like the taste of weed, man. I personally hate it but I enjoy the buzz of an edible, so there's a give and take for me.
My favorite edible's been a rice krispy treat and pretty much the same thing but made with fruity pebbles. SO FUCKING GOOD, dude, but the weedy aftertaste really sucked. I'd still eat 'em again, though.
Best I had was chocolate cake in Jamaica, Abigay was a lovely old lady with a stall by the side of the road. I don't know what her kitchen looked like but the cake was amazing I had no problem eating two slices in tandem