Start by making your spice cookies: In the bowl of a mixer fitted with a paddle attachment, cream the butter and granulated sugar until light and fluffy. Add the vanilla, salt and egg and mix well. Add the flour a little at a time, mixing well and scraping the sides of the bowl after each addition. Mix until well combined. Let chill for 30 minutes.
Preheat the oven to 350 degrees F. Line 2 baking sheets with parchment paper.
Split the dough into 3 pieces. Into one, knead the ground cinnamon in with your hand until well incorporated. Into the next dough piece, knead in the nutmeg. And into the last, the cloves.
Pick teeny tiny portions of the cinnamon dough (about the size of a jelly bean), roll them between your fingers and place on the prepared baking sheets. Repeat with the nutmeg and clove dough (making sure to keep track of the separate flavors) until you have the desired amount of little cookies (20 to 30 of each). Bake until crisp, about 10 minutes. Let cool.
Next, make the butterscotch cookie coating: In a microwave-safe bowl, heat the butterscotch morsels and 1 tablespoon heavy cream in 30-second increments, stirring every 30 seconds, until the butterscotch is melted. A touch more cream can be added if necessary. Add the corn syrup and very gently fold the mixture until it's a thin, liquid consistency, only heating the mixture for an additional period of 15 seconds or less.
Using a fork or slotted spoon (or, if you can use them, chopsticks work well), dip your cookies in the butterscotch mixture to lightly coat them (make sure you keep track of which flavor is which throughout--don't mix them up). The butterscotch creates delicious little pockets of butterscotch sauce while protecting the cookies from getting too soggy in the hot liquid panna cotta. Try to place them somewhere where the excess can drip off of the cookies a bit. Place the coated cookies in the freezer to harden, making sure not to mix up the different flavors!
Get out whichever 4 glasses you would like to present your dessert in (this recipe made enough for four 8-ounce stemmed sundae cups that we used). Wine glasses, martini glasses, tumblers, Irish coffee mugs--any of these work, but, depending on size, the layer size will vary!
The Irish cream panna cotta will be the bottom layer, so the first to make. In a small saucepan over medium heat, combine the heavy cream and vanilla. Gently bring to just a boil, then immediately remove from the heat. Sprinkle the gelatin over the cream and whisk well until the gelatin is completely dissolved and no lumps remain, at least 1 to 1 1/2 minutes. Let cool for 5 minutes, then add the Irish cream liqueur and stir well.
Divide the liquid among your 4 glasses and carefully place them in the refrigerator for 5 to 6 minutes to slightly set up. Get your cookies out of the freezer. Take out your panna cotta and add 5 to 6 of the coated nutmeg spice cookies to the layer (up to you!) and then return the glasses to the refrigerator to set up completely (will take up to 45 minutes).
The next layer will be the brown sugar maple panna cotta layer. In a small saucepan over medium heat, gently bring the heavy cream, brown sugar, maple extract and vanilla to just a boil. Immediately remove from the heat and whisk in the gelatin until completely dissolved and no lumps remain, at least 1 to 1 1/2 minutes.
Making sure that the Irish cream layer is set up, divide the brown sugar maple liquid among your 4 glasses. Return to the refrigerator for 5 minutes to set up, then add your coated cinnamon spice cookies. Chill for 45 minutes to set up completely.
The final (top) layer will be the honey panna cotta. Heat the heavy cream and honey in a small saucepan over medium heat until it comes to just a boil. Remove from the heat and whisk in the gelatin until dissolved completely and no lumps remain, at least 1 to 1 1/2 minutes. Whisk in the milk.
Making sure the other layers are completely set, divide the honey liquid among your 4 glasses. Let set up for 5 minutes, then add your coated clove spice cookies. Let the final layer set up for at least an hour.
We garnished each serving with a gingersnap cookie for a beautiful, rich holiday dessert.