Preheat oven to 350°F (175°C).
In a bowl, mix peanut butter, sugar, egg, vanilla, and baking soda until smooth.
Scoop dough into 1-inch balls, placing them on a baking sheet.
Flatten slightly with a fork, making that iconic peanut butter cookie pattern.
Bake for 10-12 minutes, or until golden and slightly firm.
While cookies bake, prepare the dipping sauce by heating cream and coffee in a saucepan.
Stir in chocolate chips and butter until smooth and glossy.
Remove from heat, then add vanilla and stir.
Let cookies cool slightly, then serve with the warm coffee chocolate dipping sauce for ultimate dunking.