Preheat the oven to 350ºF. Line a rimmed baking sheet with heavy aluminum foil and then fit it with parchment paper. Fit the matzo into the baking sheet until covered (you may have to break the matzo to make it all fit).

Place the butter and sugar in saucepan set over medium-low heat. Cook until it all melts and begins to bubble. Let bubble, stirring constantly, for 1-2 minutes. Carefully pour the mixture over the matzo, using a spatula to spread it as best as you can.

Place the baking sheet in the oven and immediately lower the temperature to 325ºF. Bake for about 10 minutes until the caramel is bubbling but the matzo isn’t looking too dark. Remove from the oven.

Sprinkle the chocolate chips over the hot matzo. Wait a few minutes, then use a spatula to spread the chocolate over the matzo. Sprinkle with the almonds, pecans, and cashews. Sprinkle with fleur de sel.

Place the entire pan in the refrigerator for 30-45 minutes until set. Break or “crack” into pieces and store in an airtight container or a large food storage bag in the freezer.