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The mere presence of hundreds of luminous quasars at cosmic dawn (redshift z>6 comma age of the Universe <1 Gyr) represents a puzzle to mechanisms of formation and early growth of massive black holes and galaxies. The central engine of these quasars is a black hole of virgul1e9 solar masses. In the local universe comma such massive black holes only reside in the most massive galaxies. Detailed optical IFU observations VLT-MUSE have indeed revealed massive and extended gaseous reservoirs fueling intense episodes of star formation in z>6 quasar hosts. At the same time comma high-resolution ALMA observations unveiled highly massive and star forming galaxies. However comma to date comma the host starlight remain elusive at such early cosmic times comma due to surface brightness and wavelength range limitations. Here we propose to perform a survey of a sample of 9 QSOs at z>6 to image their host galaxy starlight in the rest-frame optical emission (which is a robust tracer of the stellar mass). For all these objects deep MUSE and ALMA observations shows the presence of extended gas reservoirs and dust. The ultimate goal of the project is to have direct constraints on the stellar distribution in these early active galaxies comma and relate this information to the spatial distribution of gas and dust. This will allow us to investigate the interplay between star formation and the gas cycle in these systems.