I can't think of an original puzzle so let's revisit an old one. You've been blessed with perfect draws and want to get all the provinces as fast as you can in a solo game. Perfect draws means that you can effectively order the cards as you like after any reshuffle. However you are not allowed to work with a full kingdom, you can just use basic cards and cards from just 3 chosen kingdom card piles. It doesn't matter if you buy, gain, or otherwise acquire cards, the 3 pile limit (plus basic supply piles) is in force. How many turns will it take you to end the game with all eight provinces in your deck?
Usual solo game puzzle restrictions apply - no cards received through masquerade, no possession, no tribute result, no jester result, no cards in black market supply, etc. No colonies. No platinum. Any solution that makes assumptions about the other supply piles, such as upgrading a gold and receiving nothing, is invalid. Trashing a province will prevent you from solving the puzzle. I will allow outpost and the extra turn is genuinely extra. Just use some common sense for the other exceptions.
Fun example -
Turn 1 play 3 coppers, buy chancellor
Turn 2 play 4 coppers, buy worker's village
Turn 3 play a worker's village, chancellor (discard deck), play 3 copper - buy counting house, copper
Turn 4 play a worker's village, chancellor (discard deck), counting house, play 8 coppers - buy 2 worker's
Turn 5 play 3 worker's village, chancellor (discard deck), counting house, play 8 coppers - buy 2 worker's, 2 copper
Turn 6 play 5 worker's village, chancellor (discard deck), counting house, play 10 coppers - buy province, worker, 4 copper
Turn 7 play 6 worker's village, chancellor (discard deck), counting house, play 14 coppers - buy 2 province, 5 copper
Turn 8 play 6 worker's village, chancellor (discard deck), counting house, play 19 coppers - buy 2 province, 5 copper
Turn 9 play 6 worker's village, chancellor (discard deck), counting house, play 24 coppers - buy 3 provinces