Golden Egg #20 is the The Big Basket and is unlocked after achieving 3 stars on all levels of Summer Pignic.
Below is a video of the “fruity buffet glitch” that some users have experienced. Some of these users have gotten really high scores because of it (say, 140,000), but don’t expect it to happen often. It took FujiToast at least 50 tries to capture this video and his score was only 80,570, so to get the super high score will require even more luck. That said, so long as anyone can do it I’m okay with these scores.