Your specimen is A. aspersella, a rather local species, feeding on Cytisus and some further Fabaceae. Externally and in genitalia, A. atomella may be similar. But A. aspersella has no white spots on forewings, a common feature in many Agonopterix spp., also in A. atomella. And in male genitalia, best features for A. aspersella are the remarkable small socii in combination the valvae rather narrow in distal half, and large (usually touching) anllus lobes.
The one species which sounds very similar - Agonopterix adspersella - is an Apiaceae-feeder and not closely related.
Best ishes, Peter