First, whip the butter in an electric mixer for one minute on medium speed. Then add the powdered sugar and beat for 2 minutes. Add the vanilla and mix until combined.

Add the semolina, continuing to mix in the electric mixer on medium speed. Then add the all-purpose flour 1/2 cup at a time. Mix until the ingredients are evenly incorporated.

Then divide the dough into two pieces, flatten into discs, cover with plastic wrap, and chill in the fridge for at least 1 hour.

While the dough is chilling, prepare the whiskey caramel sauce. Melt the butter in a saucepan over medium heat. Then add the sugar and whisk until melted.

Add the whiskey, salt, and vanilla. Let simmer steadily for 5 minutes, stirring frequently.

Add the cream, stir, and let the sauce slowly simmer and reduce for 20-25 minutes, until it has thickened. Stir every few minutes. You want the caramel to be thick enough to for a thick layer to stick on the back of a spoon. Then keep the caramel warm on the lowest setting on your stove.

After the dough has chilled, heat your oven to 350 degrees. Remove the dough from the oven, and let it soften just enough so that you can roll it out. Roll the dough out so that it is 1/8 of an inch thick and then cut it into squares about an inch big.

Place the squares of dough on a parchment-lined baking sheet and chill them for 10 minutes before baking them on a center rack in the oven for about 8 minutes. You want to bake the dough until the edges are golden brown.

Before you turn your oven off, toast the walnuts for 2-3 minutes.

Let the cookies cool completely. Then use the shortbread cookies and the caramel to make sandwiches by spooning about 1/2 teaspoon of the caramel onto a cookie and topping it with another cookie. Make the sandwiches so that the top sides of the cookies face out (those are the smooth sides and will result in a nicer looking finished product. Once you have made all of the cookie sandwiches, prepare the melting chocolate.

Next you need to melt the chocolate in a double boiler. Fill a pot with about 4 inches of water, and heat over medium-low heat until is steaming. You do not want the water to boil. Place a glass or metal bowl over the pot, and pour the chocolate into the bowl. Stir the chocolate until it melts.

Individually pick up the cookies with a fork, and dunk them in the chocolate being sure to completely coat them. Finish the cookies off by sprinkling walnuts over the top of the cookies.

Let the chocolate set. Place the cookies in the fridge to hurry this process along if necessary.