Butter, brown sugar, and a pinch of salt is boiled together to create a superb caramel that is then spread on several sheets of matzah. The matzah is then baked until the sugary mix bubbles and then topped with chocolate. After the chocolate has had time to melt to a gooey mess from the residual heat from the toffee, you spread it evenly over the matzah.... Yum!
modified from the recipe from davidlebovitz.com