Prepare the crust. Mix the pretzel crumbs, butter, and brown sugar together. Press into a pie pan, and bake for 5 minutes at 350 degrees. Keep oven heated to 350 degrees since the pie will need to bake.

Prepare the whiskey caramel. Melt the butter in a saucepan over medium heat. Then add the sugar and whisk until melted. Add the whiskey. Let simmer steadily for 5 minutes, stirring frequently. Add the cream and let the sauce slowly simmer and reduce for 10 minutes, until it has thickened. Let cool for 5 minutes, then pour over the pretzel crust.

Prepare the chocolate filling. Combine the brown sugar, coca, and flour in a bowl. Mix together. In another bowl, combine the milk, sugar, butter, vanilla, egg, and egg white. Stir together well. Add the dry ingredients to the wet ingredients ½ cup at a time. Pour into the pie crust, over the caramel. Bake for 40 minutes, or until the center is set. It will still be a little soft, but not liquid. Remove from oven, and refrigerate for at least 4 hours before serving.

Make the whipped cream. Use an electric mixer to combine all ingredients. Mix on a medium speed until soft peaks from. Serve the pie with a generous scoop of whipped cream on each slice.