[LarvaFX]

Specifying by volume is also a problem for compressable things like flour, chopped hazelnuts etc.

[gregoryl]

For reference, this recipe is fairly tolerant, assuming you stay reasonable (don't use some sort of machine press to get your flour into the cup hey?)

[freeopinion]

The ambiguity can be solved by specifying "heaping" units. One heaping tablespoon, or 1/2 heaping cup, etc.