Start by making the pretzel crust. I used my Ninja blender to crush the pretzels, but you can also use a plastic bag and meat tenderizer or mallet. Combine the butter, egg, and sugar in your mixer. Once this mixture is creamy, add the pretzel crumbs and flour. This mix will be very dry, but that is okay!
With your hands, form a ball from the crust mixture. If the mixture is too dry, you can add a small about of water to make it easier to work with. Wrap in plastic wrap and refrigerate for about an hour. This will make it easier to roll out the crust.
After the crust mixture is cold, roll it out into a circle the size of your tart pan. I used a 12” fluted tart pan with a removable bottom, and had a little crust mixture left over. Transfer the mixture to your greased pan. This part can be a little tricky. I roll out the crust on a cutting board so that I can flip it over into the pan. It usually falls apart some, but can be easily pressed back together.
Poke holes in the crust and place in the freezer for half an hour. Cover with aluminum foil and bake at 375 for 20 minutes. Remove the foil and bake an additional 10 minutes, or until the edges are a nice golden brown.
After the crust is completely cool, start on the filling. In a small pot, melt the butter over medium heat. Mix in the heavy cream and bring to a boil. As soon as the cream mixture starts to boil, remove from heat and add in the chocolate. Whisk together until creamy and pour this mixture into the crust.
Heat the peanut butter in the microwave for about 30 seconds to thin it. Pour over the chocolate mixture in any pattern and then take a knife and swirl the chocolate and peanut butter together. This part is easier than it looks – it isn’t hard to make it look pretty!
Before you can serve your tart it needs to be cooled. Place in the refrigerator for at least an hour before serving. The chocolate and peanut butter filling will harden to the consistency of key lime pie, which makes it easy to slice and serve.