Preheat oven to 350 degrees F (175 degrees C). Spray a 9x13-inch baking dish with cooking spray.
Mix cake mix, butter, and egg together in a bowl until evenly mixed and crumbly; press into the prepared baking dish.
Bake in the preheated oven until edges of crust begin to crisp, 10 to 12 minutes.
Place marshmallows in a microwave-safe bowl; heat in microwave until melted, 20 to 40 seconds. Stir condensed milk, coconut, and almonds into melted marshmallows; spread filling evenly over crust.
Combine butterscotch chips and chocolate chips in a microwave-safe bowl; heat in microwave, stirring every 20 to 30 seconds, until melted, about 1 minute. Spread mixture evenly over filling. Refrigerate until chocolate hardens, at least 30 minutes.