Melt your butter over medium low heat in a large sauce pan.
Add in marshmallows, and stir together till marshmallows are completely melted.
Pour in your rice krispie cereal and stir together till cereal is completely coated.
Pour cereal into a 9x13 in pan and press down evenly. (Don't squish too much!)
In a medium sized sauce pan combine caramels and heavy cream over medium heat.
Stir until caramel is melted and smooth.
Pour and spread caramel evenly over the top of rice krispie treats.
Melt chocolate chips in the microwave in 30 second increments (for about 90 seconds total), stirring after each until smooth.
Pour chocolate over the caramel layer and spread evenly.
Sprinkle chopped pecans over the top of the chocolate evenly.
Let chocolate set completely and cut and serve.