Step, the digital banking service aimed at teens and endorsed by TikTok star Charli D’Amelio, announced this morning the close of a $100 million round of Series C funding after growing to over 1.5 million users just six months after launch. The new round, led by General Catalyst, comes shortly after Step’s $50 million Series B, announced at the end of last year after the startup hit half a million users in only two months post-launch. The new round also includes participation from Step’s existing investors, Coatue, Stripe, Charli D’Amelio,…