In large heavy saucepan, heat butter, cream, sugar, pumpkin puree, salt, and pumpkin pie spice on medium high heat. Bring to a boil, stirring constantly. When it begins to boil, set timer for 8 minutes.
Continue stirring while mixture is at a rolling boil.
Remove from heat. Quickly whisk in white chocolate, and marshmallow creme. Whisk until fully blended (one to two minutes). Pour into a parchment paper lined 8 or 9-inch square baking dish. Refrigerate 4 hours or overnight.
Remove from pan, remove parchment paper, and place on large cutting board. Cut into bite sized pieces.
In small bowl, whisk the caramel sauce and powdered sugar together. Drizzle over cut pieces of fudge and immediately sprinkle with crushed cookies. ENJOY immediately or store in covered container in refrigerator.
Notes
Storing: Store any fudge you won't eat right away in an airtight container in the fridge. It's delicious cold!
Crushing the gingersnaps: Put the cookies in a large ziploc bag and tap them a few times with a mallet or gently roll over the bag with a rolling pin. You don't want to turn the cookies into powder, just small enough pieces that you can fit them on each fudge square. You could also fold the crushed cookies into the fudge before pouring into baking dish.
Mixing the fudge: You don't need an electric mixer for this recipe, but using one will make it quicker and easier to combine the chocolate and marshmallow creme with the other ingredients. If whisking by hand, use a strong wire whisk and make sure the chocolate is fully melted and incorporated before you pour the fudge into the pan.
Serving: Put your fudge squares in mini cupcake liners to make serving and transporting easy!