Heavily inspired by The Crepes of Wrath's Muddy Buddy Pie, this tart is based on the childhood "Puppy Chow" treat made with Crispix, melted chocolate chips, peanut butter, and powdered sugar. Depending on how fancy you want to be, you can call it a Puppy Chow Pie or Peanut Butter-Chocolate Ganache Tart!
I found that making a snowflake out of a 8 1/2" square of paper gives you the perfect sized template to cover the top of the pie if you want to make a pretty design. —Joy Huang | The Cooking of Joy
Preheat the oven to 350°F. Use a blender or food processor to grind the cereal into fine crumbs (if using a blender, you may have to do this in batches so that you don't end up with fine powder at the bottom and large pieces on top). Mix with the melted butter, brown sugar, and salt until well combined.
Transfer the mixture to a 9" pie or tart pan and press into the sides and then the bottom. Bake for 10-12 minutes until golden, but not caramelized. Let cool while you make the filling.
In a small pot, heat the cream over medium heat until simmering. Place the chocolate chips and peanut butter in a medium, heat-proof mixing bowl and pour the hot cream over the chocolate. Stir until the chocolate has melted and the mixture is smooth. Pour into the crust and chill overnight, or at least 6 hours.
If using a snowflake template, place on top of the pie and then dust with powdered sugar. Serve small slices chilled or at room temperature.