Line a baking sheet with parchment paper; set aside.
To a medium microwave-safe bowl, add the white chocolate and heat for 30 seconds. Stop to check and stir. Heat in 15-second bursts, stopping to stir after each burst, until chocolate has melted and can be stirred smooth.
Spread chocolate into a 1/8-inch thick layer on the parchment paper. I made a 12×8-inch (approx) rectangle.
Evenly sprinkle the pretzels, marshmallows, toffee bits, peanut butter cups, and sprinkles over the white chocolate; set aside to cool. I cool at room temp but if you’re in a hurry, the fridge or freezer will speed it up.
Once cooled, break or cut the bark into pieces and serve. Bark will keep airtight at room temp for at least 2 weeks and in the fridge or freezer for many months.