Place a layer of parchment paper over the bottom of a 9-inch springform pan, and lightly spray with non-stick spray or lightly butter the sides.
Scoop the chocolate fudge brownie ice cream over the bottom of the pan, making sure to fill all the edges.
Optional: If you want distinct layers - Place in the freezer for at least 30 minutes, otherwise go ahead and sprinkle 1/2 of the small Reese's Puff Treat Bar bits over the chocolate fudge brownie ice cream
Dollop 2/3rds of the hot fudge sauce and peanut butter sauce over the Reese's Puff Treat Bar layer. (Microwave 20-30 seconds for easier dolloping.)
If you want distinct layers - return to the freezer for at least 30 minutes more.
Next, scoop the peanut butter cup ice cream over the chocolate/peanut butter saucelayer.
Add remainder of hot fudge and peanut butter sauce and Reese's Puff Treat Bar bits to the top of the dessert.
Freeze for at least 8 hours or overnight.
At least 30 minutes before serving, release the latch from the spring-form cake pan and release the ring. Place on serving platter.
Remove the cake from the freezer 10-20 minutes before serving (depending on how long it’s been frozen and how warm/cool the room is), to soften it enough to slice. A hot, dry knife will produce the cleanest cuts. To do this easily, dip the knife in a tall glass of hot water, wipe it clean with a towel, and cut a slice. Repeat before cutting the next slice. Enjoy!