I've been reliably informed that this is peanut butter and jam premixed in a jar for those too lazy to open two jars.
A goober is a type of peanut. However I'm pretty sure it's also slang for a booger.
A globule of snot and nasal mucus that hangs as a droplet from the edge of the nostril
Like a heavy raindrop suspended from his nostril, the nose goober dangled in the air; I quietly handed him a tissue.