In a small food processor or blender, crush the Pretzel Peanut Bars until crumbly.
Add the butter and blend until well-mixed.
Press mixture into an 8 x 8-inch baking pan and set aside.
In a small bowl, combine the Chocolate Brownie Shake packets, unsweetened almond milk and P3.
Blend until smooth with a whisk.
Spread mixture onto the Pretzel Peanut crust.
Top with fat-free whipped topping and sprinkle with nuts or the crushed bar.
Freeze for 30 minutes, then cut into squares and serve.