Reference : Hisn al-Muslim 53

اللّهُـمَّ صَلِّ عَلـى مُحمَّـد، وَعَلـى آلِ مُحمَّد،
كَمـا صَلَّيـتَ عَلـى إبْراهـيمَ وَعَلـى آلِ إبْراهـيم، 
إِنَّكَ حَمـيدٌ مَجـيد ، 
اللّهُـمَّ بارِكْ عَلـى مُحمَّـد، وَعَلـى آلِ مُحمَّـد،
كَمـا بارِكْتَ عَلـى إبْراهـيمَ وَعَلـى آلِ إبْراهيم، 
إِنَّكَ حَمـيدٌ مَجـيد
Allāhumma ṣalli `alā Muḥammadinwa `alā ’āli Muḥammadin, 
kamā ṣallayta `alā 'Ibrāhīma wa `alā ’āli 'Ibrāhīma, 'innaka ḥamīdum-majīd.
Allāhumma bārik `alā Muḥammadin wa `alā ’āli Muḥammadin, 
kamā bārakta `alā 'Ibrāhīma wa `alā 'āli 'Ibrāhīma, 
'innaka ḥamīdum-majīd.


O Allah, bestow Your favor on Muhammad and on the family of Muhammad as You have bestowed Your favor on Ibrahim and on the family of Ibrahim, You are Praiseworthy, Most Glorious. 
O Allah, bless Muhammad and the family of Muhammad as You have blessed Ibrahim and the family of Ibrahim, You are Praiseworthy, Most Glorious.

Reference:
Al-Bukhari, cf. Al-Asqalani, Fathul-Bari 6/408.

Chapter: Prayers upon the Prophet ﷺ after the tashahhud