Grease a 9 x 13-inch baking pan. It's also helpful to grease the pot and utensils you are using to melt the marshmallows.
Combine the butter and marshmallows in a large saucepan and cook over medium-low heat, stirring frequently until melted. Remove from heat, stir in the vanilla, then the cereal. Stir until cereal is completely coated and pour into greased pan. Wet hands to press the mixture into the pan. Place in refrigerator to chill.
In a small saucepan, heat caramel sauce and water over medium-low heat, until warmed. Stir in 1 cup of the peanut butter until completely smooth. Pour over chilled cereal mixture and spread to the edges. Place pan back into fridge.
Over medium-low heat, melt chocolate in a small saucepan, stirring frequently so as not to scorch the chocolate. When melted, add the remaining 1/2 cup peanut butter, stirring until smooth. Pour chocolate mixture over the caramel layer and spread to the edges. Place pan in the fridge to chill for about an hour or until chocolate is firm. Cut into squares. Keep in fridge.
https://simplycleanandfitmom.com/2013/11/chocolate-caramel-and-peanut-butter-rice-krispie-treats/
(Source: Adapted from piarecipes.com)