Grab a 9×13-inch baking tin and line it with parchment paper or aluminum foil.
Lay out your crackers in a single layer, edge to edge, like a little puzzle.
Make the caramel. In a medium-sized pot, melt the butter and brown sugar together over medium heat. Stir it constantly until it starts bubbling (rolling boil).
Carefully pour that hot, buttery caramel over your crackers, making sure to cover every inch. Use a spatula to spread it evenly if needed. Pop the pan into a preheated oven at 350°F (175°C) for about 5 minutes. Keep an eye on it, you want the caramel to bubble up but not burn.
As soon as you pull the pan out of the oven, sprinkle your milk chocolate over the hot caramel. Wait a minute or two for the chocolate to soften, then use a spatula or the back of a spoon to spread it out into a smooth, glossy layer.
Sprinkle crushed Oreos, M&M’s, and white chocolate buttons over the melted chocolate. You can be as precise or as chaotic as you like here.
Let the whole thing cool at room temperature for about 30 minutes. Then pop it in the fridge for at least an hour to set. If you’re in a hurry (or just impatient like me), the freezer works too.
Once it’s fully hardened, lift it out of the pan using the parchment paper or foil. Break it into pieces, big, small, or somewhere in between.
