In a food processor, blend 3 cups of peanut butter pretzels with 6 tablespoons of softened unsalted butter until you get fine crumbs resembling wet sand. Press this mixture evenly into the bottom and up the sides of an 8-inch tart pan. Spread a layer of creamy peanut butter on top and then place it in the freezer as you move on to the next step.
In a medium saucepan, combine 2 cups of chopped dark chocolate and 1 cup of heavy cream over medium heat. Stir constantly until the chocolate completely melts, creating a smooth ganache. This takes about 4 minutes. Pour the ganache over the peanut butter layer and return the tart to the freezer to set for 45 minutes.
Once set, garnish your creation with flaky sea salt and chopped roasted peanuts. Then, simply slice and serve this decadent Chocolate-Peanut Butter Pretzel Tart to enjoy the perfect blend of sweet and salty flavors!