Peanut butter and honey is the peanut butter sandwich with the dryness answered by a runny sweetener, and the honey is what defines both its appeal and its difficulty. Peanut butter alone is thick, savoury, and parching; honey poured over it adds an immediate sweetness and a fluid that loosens the claggy fat so the filling slides rather than sticks. That is the upside. The downside is built into the same property: honey is liquid and goes more liquid against the warmth of bread and a hand, so the very thing that fixes the dryness is also the thing that runs out of the sides, and the whole craft of this sandwich is containment.
The craft is therefore about holding a moving filling still. The peanut butter is spread thick and edge to edge first and the honey is pooled into the centre of that layer, never the reverse, because the dense peanut butter acts as a levee that keeps the honey from reaching the crust and bleeding straight through the crumb. The honey goes on in a measured thread, not a generous pour, because there is no second structural element here to absorb excess the way banana or jam partly would, and too much simply escapes under the top slice. Soft white bread is used because chew adds nothing the filling needs, and the sandwich is best eaten soon after it is made, since honey continues to migrate into the bread the longer it sits and a packed-ahead version arrives sweet but soggy at the seam.
The variations stay inside the sweet, soft frame. Banana added alongside gives the honey something to cling to and slows the run; a thicker set honey behaves more like jam and contains more easily; the wider sweet family of jam, banana, and golden syrup keeps the same buttered-soft logic. Each deserves its own article rather than being crowded in here.