4. dxe5 is not so good:
forcing the retreat of the white knight and followed by Qxd5.
We have the following interesting continuation:
The sequel leads to a knight sacrifice but with a sufficient positional compensation:
Here white could continue with Qh3+, Qg4+ or Qf5+.
If U start with Double Bongcloud
then Elephant Gambit becomes an optimal option. 
