Sa'eed bin Abi Sa'eed Al-Maqburi narrated that Abu Salamah informed him that he had asked Aishah: "How was the Salat of Messenger of Allah (A) [at night] during Ramadan?" She said: "Messenger of Allah (S) would pray - neither in Ramadan nor in any other month - more than eleven Rak'ah. He would pray four, and do not ask about their excellence or length, then he would pray four, and do not ask about their excellence or length, then he would pray three." Aishah said: "I asked: 'O Messenger of Allah! Do you sleep before having performed Witr?" He said: 'O Aishah! Indeed my eyes sleep but my heart does not sleep.'"  

أَنَّهُ أَخْبَرَهُ أَنَّهُ سَأَلَ عَائِشَةَ كَيْفَ كَانَتْ صَلاَةُ رَسُولِ اللَّهِ ﷺ بِاللَّيْلِ فِي رَمَضَانَ فَقَالَتْ مَا كَانَ رَسُولُ اللَّهِ ﷺ يَزِيدُ فِي رَمَضَانَ وَلاَ فِي غَيْرِهِ عَلَى إِحْدَى عَشْرَةَ رَكْعَةً يُصَلِّي أَرْبَعًا فَلاَ تَسْأَلْ عَنْ حُسْنِهِنَّ وَطُولِهِنَّ ثُمَّ يُصَلِّي أَرْبَعًا فَلاَ تَسْأَلْ عَنْ حُسْنِهِنَّ وَطُولِهِنَّ ثُمَّ يُصَلِّي ثَلاَثًا فَقَالَتْ عَائِشَةُ فَقُلْتُ يَا رَسُولَ اللَّهِ أَتَنَامُ قَبْلَ أَنْ تُوتِرَ فَقَالَ يَا عَائِشَةُ إِنَّ عَيْنَىَّ تَنَامَانِ وَلاَ يَنَامُ قَلْبِي  

"Messenger of Allah (S) would pray eleven Rak'ah at night, making them off with one. When he finished them he would lay down on his right side."  

أَنَّ رَسُولَ اللَّهِ ﷺ كَانَ يُصَلِّي مِنَ اللَّيْلِ إِحْدَى عَشْرَةَ رَكْعَةً يُوتِرُ مِنْهَا بِوَاحِدَةٍ فَإِذَا فَرَغَ مِنْهَا اضْطَجَعَ عَلَى شِقِّهِ الأَيْمَنِ  

Another chain with similar narration