Try to reach the position in exactly 4 (four) moves. No more, no less. :D
lichess.org/editor/rnbqkbnr/pp3ppp/2p1p3/8/4P3/8/PPPP1PPP/RNBQK1NR_w_-_-(those who know the solution: let the others burn for a while :) )
I know the solution. Can I double the burn?
This one also after black's 4th move (one of my old compositions):
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lichess.org/editor/rnbqkbnr/pppp3p/4p1p1/8/3P4/8/PPP1PPPP/RNB1KBNR_w_-_-Not 3 and not 5 - this would be way too easy...
"Exactly 4" refers to "4 full moves", right? As in, it's White to move in the given situation?
8 plies if this helps you.
I didn't find the first one that hard: 1.e4 e6 2.Bb5 Ke7 3.Bxd7 c6 4.Be8 Kxe8. The key was to understand that black has to spend one move each on e6 and g6, so if he had to spend another on dxe6 or dxc6, he'd need to make a fourth move without changing the position (this is not possible). Then you realize that black doesn't capture anything with his pawns, so the bishop must be captured by another piece and from there it's not hard.
I'm still thinking about the second one though, the queen seems to be much trickier :)