Preheat the oven to 350 degrees F. Lightly grease four 5-inch creme brulee ramekins, each with 1/2 tablespoon of the butter.
Cut the slices of bread in half as you would cut a sandwich (either down the middle or on a diagonal)--you'll use 3 slices for each portion.
Spread the peanut butter on 4 of the pieces of bread. Spread the jelly on 4 of the remaining pieces and stack them on the peanut butter pieces, laying them slightly askew. Top each stack with 1 piece of the remaining bread. Transfer each to a prepared ramekin.
In a medium bowl, whisk the eggs, cream, the 3 tablespoons brown sugar, the maple syrup, cinnamon and salt together to combine. Gently pour or ladle 1/4 of the mixture over each portion, coating the top layer of bread. If desired, sprinkle each portion with a pinch or two of brown sugar.
Place the ramekins on a rimmed baking sheet and bake until the bread looks gently toasted at the edges, but still soft in the center, 15 to 20 minutes. Remove from the oven and let cool for 5 minutes, then sprinkle with confectioners' sugar and serve.