1. Preheat the oven to 350 degrees Fahrenheit. Grease an eight-inch square baking pan with nonstick spray. Line the pan fully with foil that hangs over all sides like a handle (two long pieces lined crosswise). Spray or butter the foil generously (but not the handles).
2. In a deep saucepan over medium heat, melt brown sugar with butter to create the caramel. Once it is all dissolved and begins a low boil, time it for three minutes and don’t stir the mixture.
3. Use one whole sheet of matzo for each layer in the pan. Place a matzo in the bottom of the greased pan. When the caramel is ready, pour on a thin layer and, using an offset spatula, spread it quickly. Be careful—it is quite hot. Quickly place another whole matzo on top and repeat until you run out of matzo or the caramel. Bake for 15 minutes.
4. While that bakes, get the other ingredients ready to go. Once the matzo comes out of the oven and while it is piping hot, top with half of the chocolate chips followed by half of the coconut flakes, and then half of the nuts and half of the mini marshmallows. Repeat. End with a few strategically placed marshmallows, coconut, chocolate chips, and nuts on top so it looks attractive.
5. Bake for five to seven minutes more, or until the marshmallows just start to become golden. Remove from the oven. Let cool thoroughly in the pan for three to four hours. Using the foil handles, transfer from the pan onto a cutting board. Peel away the foil. Gently slice, using a serrated knife.