In a food processor, break down a sleeve of graham crackers. Pulse for a good two minutes until they reach a fine, flour-like consistency, making sure there are no large crumbs left.
In a large bowl, combine the finely crushed graham crackers with the melted butter, peanut butter, powdered sugar, and vanilla extract. Mix until everything is well incorporated.
Line two cupcake tins with cupcake cups. Fill each cup with a heaping tablespoon of the peanut butter mixture. Gently shake and bang the tins on the counter to settle the mixture and even out the tops. Transfer the tins to the freezer to chill while you make the caramel.
For the caramel, add the sugar to a small pot with tall sides. Stand by and watch it for a couple of minutes until the edges of the sugar begin to melt. Swirl the pot gently – don't stir – and continue cooking until the sugar reaches a deep auburn color.