Warm the cream and butter together in a small pan until steaming, then keep them beside the stove.

Stir the sugar and water in a heavy saucepan over medium heat until the sugar dissolves, then stop stirring and boil to a medium amber, 6 to 8 minutes. Slide the pan off the heat and pour in the warm cream and butter, standing back, because it will boil up hard.

Return the pan to medium heat and cook to 245F on a candy thermometer, about 3 to 4 minutes, then take it off and stir in the bourbon and salt. Leave it to cool to room temperature, about 30 minutes; it thickens considerably as it drops.

Beat the peanut butter, confectioners sugar and softened butter on medium-low with the paddle attachment until smooth and stiff.

Add the bourbon, vanilla and salt and mix until combined, then scrape the filling into a piping bag, or a zip-top bag with about half an inch snipped off one corner.

Melt the chocolate in a bowl set over barely simmering water, stir in the espresso powder, then turn off the burner and leave the bowl over the water so it stays fluid while you work.

Paint the base and up the sides of each candy cup with a small spoon or a pastry brush, set them on a rimmed sheet pan and freeze until firm, about 10 minutes. Go a second time over any shell you can see light through.

Pipe the peanut butter filling into each chilled shell, three quarters of the way up.

Spoon about half a teaspoon of the cooled caramel onto each one, then cover with a thin layer of the melted chocolate and rap the tray on the counter two or three times so the tops level themselves. Scatter with sprinkles now if you are using them.

Freeze until set, about 15 minutes, then store the candies refrigerated or frozen in a sealed container.