Prepare a 9 x 13 inch pan (useful if the pan has straight sides, like this) by lining it with parchment paper, leaving the long sides slightly long so that it can be used to remove the stencils later . . Spray parchment and sides of pan with nonstick spray.
Coat the bottom of the pan with the first layer of crackers on parchment. Cut crackers as needed. I used five rows of six crackers to cover my pan perfectly. In a medium heavy-bottomed saucepan, melt butter, brown sugar, graham cracker crumbs, and thickened cream over medium heat, stirring constantly.
Bring the mixture to a boil while continuing to stir and simmer for 7 minutes.
Pour half of the caramel mixture over the crackers, spreading them evenly around the edges of the pan. Working quickly, add another layer of crackers on top of the caramel.
Pour the remaining caramel over the second layer of crackers, then add the last layer of crackers. Place the pan in the fridge to cool and layer the caramel while preparing the chocolate filling.
To prepare the chocolate filling, add the milk chocolate chips, butterscotch pie, and peanut butter to a microwave-safe bowl. Heat for 30-45 seconds, then stir well. Heat the chocolate in the microwave every 15 seconds, stirring until smooth. Pour the chocolate filling over the last layer of the cookie, spreading it evenly around the edges. Sprinkle sea salt over the chocolate layer as desired. I used about 1 tsp.
Place in the fridge for 1-2 hours before using a sharp knife to cut into bars. Sometimes I like to use the edge of the stencil to lift things out of the pan for easier cutting.