Deviating from standard Danish gambit I like to play the Danish gambit opening. Frequently, black won't take the last pawn to complete the standard opening, but instead plays the knight as shown below. I'll generally play Queen to b3 or f3. But then black plays Knight to a5 or e5, respectively, which results in losing the c4 bishop. Is there a nice way for white to respond to Nc6?

[fen "r1bqkbnr/pppp1ppp/2n5/8/2B1P3/2p5/PP3PPP/RNBQK1NR w KQkq - 0 1"]
Just develop your pieces. 5.Nf3 makes sense, preparing to castle. 5.Nxc3 is also reasonable; if Black refuses to play ... cxb2, you'll probably have to play Nxc3 at some point anyway. These are the only two regularly played moves in the given position.