Kane, 18 goals in 21 Champions League games (3 seasons at Spurs).Lewandowski is a specimen though, Kane is a goalscoring Rodri with ankles made out of paper mache.
Lewandowski in the same period, 28 goals in 29 Champions League games (All 3 seasons at Bayern).
Lewandowski at the same age, 22 goals in 34 Champions League games (2 seasons at Dortmund, 1 at Bayern).
I would say the goalscoring Rodri holds up pretty well against him.
Not using league form as Lewandowski is a seasoned farmer but Kanes form was better for Spurs than Lewandowski at Dortmund. Lewandowski's record took a huge upward swing once he became a professional farmer at the league's dominant team.
Lewandowski just got the move to the dominant team a couple of years earlier due to better advisors, Kane's stats will massively increase in our side and he was already top goalscorer and assister last year!