Does anyone know a Yaoi manga in which there is a huge difference In age like 10 between t...

Try works by Naono Bohra
http://www.mangago.zone/read-manga/nights/
http://www.mangago.zone/read-manga/yume_musubi_koi_musubi/
http://www.mangago.zone/read-manga/boku_no_shiru_anata_no_hanashi/ (I think this mangaka has other with huge age gap)
http://www.mangago.zone/read-manga/miwaku_no_ringo/ (also the work of this mangaka)
http://www.mangago.zone/read-manga/melancholy_melancholic_melancholinist/
http://www.mangago.zone/read-manga/kuroneko_wa_shippo_de_amaeru/ (this mangaka also)
http://www.mangago.zone/read-manga/otokogokoro/ (this mangaka also has a few other)

I'm not really sure they were 10 years apart though, but manga with age gap;

http://www.mangago.zone/read-manga/hana_wa_saku_ka/
http://www.mangago.zone/read-manga/castle_mango/
http://www.mangago.zone/read-manga/super_lovers/
http://www.mangago.zone/read-manga/ore_ni_koi_shite_dousunda/
http://www.mangago.zone/read-manga/doushiyoumo_nai_keredo/
http://www.mangago.zone/read-manga/hanaya_no_nikai_de/
http://www.mangago.zone/read-manga/sora_to_hara/
http://www.mangago.zone/read-manga/mankai_darling/
http://www.mangago.zone/read-manga/aozora_no_sunda_iro_wa/
http://www.mangago.zone/read-manga/otokogokoro/
http://www.mangago.zone/read-manga/boku_no_shiru_anata_no_hanashi/

I dont remember the exactly age gap but here
http://www.mangago.zone/read-manga/otokogokoro/