Instructions
Go to Costolot's General Store once you reach Level 4. Purchase a chili seed for 22 coins and a gooseberry seed for 22 coins.
Go back to your garden and plant the chili seed in grass or soil. Use red fertilizer three times on the area where you planted the chili seed to make it grow more quickly.
Plant the gooseberry seed in long grass, grass or soil. Use one dose of green fertilizer on the area where you planted the gooseberry seed. Wait for the bush to shake off a few leaves, then give it another dose of green fertilizer. Give it one last dose of green fertilizer when it shakes its leaves again.
Wait for a Rashberry to appear. This pinata will show up once your chili plant and gooseberry bush are fully grown. Go to Bart's Exchange store in the village. Purchase a block of cheese.
Use the Tinker ability to transform the cheese into cheesecake. Feed the cheesecake to the Rashberry and it will transform into a Hoghurt.