Preheat oven to 350F. Line two large baking sheets with parchment paper and set aside.
In the bowl of a stand mixer OR with a handheld electric mixer, beat butter and sugars together until completely creamy, about 1-2 minutes. Beat in peanut butter, egg, and vanilla until smooth.
In a medium bowl, combine flour, baking soda, cinnamon, and salt. Mix flour mixture into butter mixture until a soft dough forms. Fold in rice krispie cereal and chocolate chips.
Scoop dough into 1-in balls and place 1-in apart on prepared baking sheets. Bake cookies at 350F 9 minutes, then remove from oven and tap pan on counter several times to flatten cookies. Return cookies to oven for an additional 3-4 minutes or until edges are lightly browned.
Top cookies with a sprinkle of sea salt if desired. Cool cookies on pan 10 minutes then transfer to a wire cooling rack to cool completely. Enjoy!