Preheat oven to 375°.
Line a jelly roll pan with aluminum foil; cover foil with parchment paper. Arrange matzo crackers in a single layer on pan, cutting them as necessary to fit; bake at 375° for 5 minutes or until crackers are lightly browned. Reduce oven temperature to 350°.
Combine butter and brown sugar in a small heavy saucepan; bring to a boil, stirring often. Cook 3 minutes, stirring constantly; pour mixture over matzo. Bake at 350° for 10 minutes or until the mixture bubbles. Sprinkle evenly with chocolate. Cool slightly; refrigerate 30 minutes or until chocolate is set. Break into 36 pieces.