Toss pretzel crumbs with melted butter, then press into a 10-inch pie pan. Bake at 350° for apx. 10 mins. Allow to cool
Bring 1/3 cup of heavy cream just to a simmer, then remove from heat and add chocolate chips; stir until smooth and set aside.
Using the paddle attachement on your mixer, beat peanut butter and cream cheese until combined. Add 1/2 sugar and beat until thoroughly incorporated (no graininess.)
Using a clean bowl, whip cream until it just begins to thicken; continue to whip as you slowly add in the 1/3 cup of sugar. Whip until the cream is fluffy... then stop! You want to be careful not to overbeat.
Using a gentle touch, slowly fold half of the whipped cream into the peanut butter mixture. Repeat with second half of the whipped cream.
Add the caramel to your cooled pretzel crust; chill until set (apx 10 minutes). Repeat this step, this time adding the chocolate. Finally, top with the peanut butter mixture and a sprinkling of the reserved chocolate and pretzels.