Arrange the matzo crackers on a parchment lined baking sheet. Break or cut the crackers in half or in to pieces to fill the baking sheet. (Don’t worry about it being neat, just try to get the area filled in a single layer!)

In a large, heavy bottomed pot (at least 3 quarts) fitted with a candy thermometer, combine the butter, sugar, and salt over medium heat. Stir with a heat proof non-stick utensil until the butter is melted and incorporated. Bring to a boil and cook, stirring occasionally, until the mixture reaches 290F on the candy thermometer, a dark amber brown. Remove the toffee from the heat and stir in the salt and vanilla extract.

Immediately pour the toffee over the prepared matzo. Sprinkle the chocolate over top of the hot toffee and wait 1-2 minutes until the chocolate begins to melt. Use a spatula to spread and smooth the chocolate into an even-ish thin layer. Sprinkle the chopped pecans and onto the chocolate’s surface, and use your flat palm to press the nuts in slightly (this will keep the nuts from falling off when the matzo is broken into pieces later.) Let cool for about 5 minutes, the sprinkle on the flake salt. (If the salt is added immediately, it will dissolve. It is important that the chocolate has cooled slightly to prevent this!)

Transfer the baking sheet to the fridge, and allow to set completely. When set, break into pieces and store in an airtight container.