1 1/2 cups kumquats
1 1/2 cups sugar
1 1/2 cups water
5 sheets matzo
1 cup unsalted butter
1 packed cup brown sugar
hefty pinch salt (plus additional coarse salt for topping, optional)
1/2 teaspoon vanilla
1 heaping cup chocolate chips or finely chopped chocolate
To candy the kumquats: Slice the kumquats quite thin, flicking out any seeds (they'll fall out in the process too, and are also edible, so don't worry too much). Bring the sugar and water to a simmer in a pot, then add the kumquats, reducing the heat until it's just enough to maintain a simmer. Cook, stirring once or twice, until the kumquats have become translucent, ~20 minutes. Remove with a slotted spoon, and place on a rack to drain.
While the kumquats are drying off a bit, prepare the matzoh crunch. Line a rimmed baking sheet with foil, and lay out the matzoh (break as needed to fit). Preheat your oven to 350 Fahrenheit.
In a large saucepan, melt the butter and sugar together over a medium-high heat. Bring to a simmer, and let simmer for 3 minutes, stirring constantly. Remove from heat, and add the salt and vanilla. Pour the hot mixture over the matzo, spreading with a heat-proof spatula to cover evenly.
Transfer the matzo to the oven, and bake for 15 minutes (it'll bubble up a bit during the baking). After 15 minutes, remove from the oven, and scatter the chocolate evenly over the top. Let sit 5 minutes, then spread the chocolate evenly with an offset spatula. Top with a paving of the kumquat slices, pressing into the warm chocolate slightly. Sprinkle with a bit of coarse salt if desired.
Let cool fully (you can speed this up in the refrigerator if you're impatient), then break or cut into chunks.