Line a cookie sheet with waxed paper. Place butterscotch chips in a microwave safe bowl and heat on 50% power for 1 minute, stir, and then add increments of 30 seconds until chips are melted and smooth. Spread on cookie sheet.
Sprinkle Rice Krispies cereal on top of butterscotch layer. Press down with your hands.
Melt semi-sweet chocolate chips in microwave, again using 50% power, stirring after 1 minute and continuing to heat at 30 second intervals until chips are melted. (If chocolate doesn’t seem smooth, add about a teaspoon or two of vegetable oil and stir.) Spread over Rice Krispie layer.
While spreading chocolate layer, melt peanut butter in microwave. Drizzle over spread chocolate and swirl with the back of a spoon.
Chill to harden bark, then break into pieces and serve.
