Preheat oven to 350ºF. Line a baking sheet with foil and oil very lightly. Spread the matzos in the pan in a single layer, breaking them to fit, so it fills the pan.
Heat the butter and brown sugar in a medium saucepan to a boil until it begins to carmelize and is a rich, light-brown color. Pour evenly over matzo, spreading with a spatula to make sure the matzo is well covered. Bake 10 to 15 minutes until the caramel is a golden brown.
Meanwhile, finely chop the walnuts. You want to chop until you have a mix of small pieces and a finer dust-like leftover.
When the caramel is golden brown, remove the matzo and turn off the oven. Sprinkle the chocolate chips evenly over the matzo.
Return the matzo to the oven. Let it sit in the warm oven for 5 minutes. Remove and spread the chocolate evenly with the back of a flat spatula or a knife.
Top with nuts, if using. Sprinkle with the salt. Allow to cool for 30 minutes.