01 - 
                Get an 8-inch square pan (20x20 cm). Lay parchment paper inside and spritz a little nonstick spray on top. Move it aside for now.
              
              
              
                02 - 
                Put salted butter, marshmallow crème, sweetened condensed milk, sugar, and caramel syrup in a medium pot. Set the heat to medium-high. Keep stirring, don’t walk away, until you see bubbles.
              
              
              
                03 - 
                As soon as it boils, stir on a steady pace for 4 minutes. The mix will get thicker and turn a warm golden color. Toss in those butterscotch chips and keep stirring until everything’s melty and blended. Take off the heat, whisk for another minute or two so it cools a bit but still pours easily.
              
              
              
                04 - 
                Pour the butterscotch fudge into your pan, smoothing it right to the corners. Let it hang out in the freezer while you get the next layer started.
              
              
              
                05 - 
                For the top layer, grab a clean saucepan and add sugar, butter, marshmallow crème, and sweetened condensed milk. Turn the heat to medium and don’t stop stirring until the mix bubbles up.
              
              
              
                06 - 
                Once you see it boiling, dial down the heat a bit and keep mixing for 2 minutes. Take off the heat. Quickly dump in white chocolate chips and gently stir till you’ve got a smooth blend. No need to keep stirring so much—it can mess up the texture.
              
              
              
                07 - 
                Right away, pour the white chocolate mix onto the cold butterscotch layer. Use a spatula to spread it out even, edge to edge.
              
              
              
                08 - 
                Stick it in your fridge for a few hours (2 to 3) or speed things up in the freezer for an hour until totally set and hard.
              
              
              
                09 - 
                Once it’s chilled, pop it out of the pan and slice into 49 chunks (about one inch each). Dig in right away.